LongBench v2 / 670fb813bb02136c067d2bec / Please try to deduce the true story based on the evidence currently known. In…

Prologue: Introduction

"Unbelievable!"

After hearing my account, the boy shook his head and said this. Honestly, his reaction was justified.

"If I were joking, I wouldn't have come to discuss this with you."

I didn't directly say I wasn't lying; instead, I deliberately answered in a roundabout way. At least, I wasn't lying—I was serious.

I truly wanted to frame the person in front of me.

The boy touched his neatly trimmed bangs, seeming a bit troubled. Shouts from the sports teams' activities could occasionally be heard from across the wall, and his eyes vigilantly darted around whenever this happened. In reality, there was no need to worry about being seen. We were meeting behind a historic gymnasium, even though the content of our conversation had nothing to do with the dazzling youthfulness.

"What if I'm not willing?"

"Then forget it, even if I'm not content."

The boy looked at the stiff black bag slung over his right shoulder. It was a camera case. This guy definitely wouldn't refuse; I had understood his personality perfectly, and I believed I had the ability to see through people's true nature.

"What should I do?"

Soon, the boy resolved himself and looked up. See, just as I thought.

I succinctly explained the time and place, and gave a few details.

While I was speaking endlessly, I was also reviewing the plan in a corner of my mind. No problem, not a single flaw. No one would notice I was the culprit. For me, who was in a disadvantaged situation, this was a major reversal. Eliminate the culprit and let everything return to its original, stable state.

Erase him, then take "that"—

The boy nodded to each of my instructions, not feeling uneasy about how everything was too perfectly in place. I easily handled this matter.

Lastly, I apologized for calling him out for such an incomprehensible matter. Upon hearing this, the boy honestly smiled and said:

"No problem. Ignoring this would be unfair... Thank you for telling me."

I couldn't help but smile too and bowed my head. This was a gesture of respect mixed with full disdain for the pitiable hero who was about to trigger a tragedy.

"Then I'll leave it to you—Asajima."

The flawless criminal act completed its preparations just like that.
Chapter 1: Beginning with a Case - 1 The Rising Curtain Is the Opening Act

"Oh dear, it's raining so hard."

Yuzuno seemed to hear Sanae, who was running ahead of her, mumble something to this effect. The heavy rain relentlessly pounded the ground, and the sound made it difficult to clearly hear what she was saying. However, she was certainly complaining about the bad weather. If Yuzuno didn't hear wrong, she completely agreed with Sanae's opinion.

A torrential downpour.

It was currently the rainy season, and the advancing monsoon front launched a fierce attack. The weather forecast the day before had predicted cloudy skies for today, but it had been inaccurate. It started raining from early morning. The meteorologist said the rain would likely continue until nine in the evening. Although the forecaster wore a salesperson-like smile, no one could smile back at this news.

It was now 3:07 PM.

The thought of this heavy rain continuing for another six hours was depressing. 

"Oh dear, got soaked… We should have brought an umbrella."

Sanae arrived at the small entrance of the first teaching building first, shaking her head like a small dog or cat to shake off the rain. Yuzuno also ran in and stood beside her. 

The training clothes they had just gotten in May were soaked through, sticking to their bodies. Their indoor shoes were covered in mud and looked terrible. It was little more than ten meters from the club activity building to the teaching building, so they thought running over would keep them dry, but they had miscalculated.

Their umbrellas, bags, and school uniforms were crammed into the club's locker room. All they had on them now were sports drinks, paddles, table tennis shoes, and towels in storage bags—the four essential items for club activities. 

They wrung the water out of the hems of their training clothes. The letters printed on their chests—"Kazeno Hill High School Girls' Table Tennis Team"—were wrinkled and crumpled.

"I hate rainy days because of this!"

Sanae was still grumbling.

"Well, it can't be helped. Let's go quickly."

Sighing wouldn't change anything at this point, so Yuzuno decided to adjust her mood. They wiped the mud off their indoor shoes on mats and headed for the corridor. The first teaching building, just after the bell had rung, was crowded with students heading for the exits.

"Oh hoho!" A voice called from behind, like someone shouting from the top of a mountain. When they turned around, they saw members of the table tennis team still in their school uniforms coming down the stairs.

"Yuzuno, you're quick!"

"It's our turn today to do the preparation work."

"Oh, I see. Then we'll leave setting up the tables to you!"

Their friends waved and headed toward the club activity building. They would leisurely change clothes and by the time they reached the gymnasium, preparations would be done—Yuzuno noticed this sense of victory. But the duty alternated every day, so Yuzuno and the others usually enjoyed this leisure.

"Are we going to be the first ones to the gym?"

Sanae said. The boys from the baseball team clattered noisily beside them, making it hard to hear what she was saying, just like the sound of rain. Yuzuno raised her voice so Sanae could hear her:

"Maybe Nao is already there!"

By the time they reached the activity room, there was already a bag on the ground. Their senior must have finished changing and gone to the gym before them. She was always like that.

Nao Sugawa.

Second-year student, captain of the table tennis team.

Gifted and wise, straightforward and open-minded. Yet, she didn't just recklessly charge forward; she had a calm and collected side. Nao could be described with four direct words: "dedicated to training."

She never missed either morning or afternoon practice. What's more, she always changed into her training clothes and arrived at the gym first. She would start stretching exercises and help with preparations when the juniors on duty arrived. By the time the other team members gathered, she was already discussing training contents with the coach.

Her skill and enthusiasm were proportional. Even as a first-year student, she ranked eighth in the entire prefecture's singles during last year's newcomer competition. For Kazeno Hill High School's average-level table tennis team, she was undoubtedly a rare powerful punch. Competing in inter-high school competitions was no longer a fantasy, and even ace players from strong schools considered her a rival.

She became the captain about a month ago when the third-year students retired. At that time, her trust among the team members was already outstanding. Just the moment Yuzuno and the others stepped into the gymnasium, the short-haired athletic figure would feign anger and call out “Why are you two so late?”—this scene seemed to have appeared in Yuzuno’s mind.

Wiping her damp hair with a towel, a smile appeared on Yuzuno's face.

The girls’ table tennis team’s activity area, the old gymnasium, was located deep inside the school, next to the third teaching building. Far from the entrance, there weren’t many people around.

They passed unnoticed doors like the language textbook room, the restrooms for teachers and guests, and the student council storeroom. Before reaching the end of the corridor, they turned left and arrived at the short passage connecting the teaching building and gymnasium. It was called a corridor, but it really was just a roof over the concrete path. Nonetheless, simply being able to avoid the rain was enough to make them cry with joy.

The gymnasium doors were open, revealing what was inside from the end of the corridor.

Sure enough, Captain Sugawa was indeed there. She was inside, doing stretching exercises next to the advisor.

"You see, she’s already here, isn’t she?"

"Indeed. As expected of the captain... Oh, the rain has let up a little."

Listening to what Sanae said, Yuzuno looked outside the corridor and indeed felt the rain had lightened somewhat.

"It’d be nice if the rain stopped before we head home..."

As she moved her gaze from the gray sky, she noticed a girl standing by the window of the gym’s restroom on her left, under an umbrella, with blonde hair and a frowning face that said, “I’m fed up with this rain.”

But speaking of which, why would she stand in such a place? If waiting for a friend, the entrance with a roof would be much more comfortable—

Just as she was puzzling over this, a shout reached her:

"Why are you so late, you two?"

It was the captain who had spotted Yuzuno, and she was calling them. This booming voice blew away Yuzuno’s confusion in an instant. The loud voice that matched her breezy appearance resounded in the gym. Yuzuno and her companion apologized in unison as they changed shoes and stepped inside the gymnasium.

This was the truly "old" gym, an aged building.

The tall ceiling with intersecting steel beams, the basketball hoops at equal intervals, the lines of various colors on the floor. When their table tennis shoes pressed forcefully down, it made a delightful "chirp" sound. In this place that was filled with a unique scent, enveloped in a unique atmosphere, there wasn’t a single soul except for them. Against the backdrop of the rain's sound outside, the familiar scenery somehow seemed a bit lonely.

"…Hmm?"

Scanning the entire gymnasium, she noticed something else besides the lack of people. Something that was different from usual.

The stage’s curtain was down.

Near the left-hand side when entering through the main entrance, there was a stage approximately one meter high. With a podium on it, it was always ready for someone to deliver a speech or talk. This space, which generally made the gym seem larger, was now shielded by a heavy, crimson curtain, concealing what lay behind.

Why was this? Even during drama club rehearsals, it was rare to have the curtain drawn down.

However, this doubt was blown away by Sanae’s words.

"We’re late, you say, it's only 3:10 PM. We did try hard."

Sanae pointed at the clock next to the stage. The captain mischievously grinned and said:

"That's late! I was here by three."

"…Three, that’s right at the end of class! Did you teleport?"

"We finished class early."

"Haha... As expected of the captain."

Though finishing class early wasn’t related to the captain’s prowess, they somehow felt admiration.

"Then please get the tables ready."

Advising teacher and coach, the young teacher Shintaro Masumura urged them. Yuzuno and her friends put down their paddles and towels, heading towards the equipment storeroom, and the captain followed them to help.

"I’ll bring the ball machine, so please set up the tables."

Speaking while picking up the ball machine for practice, she quickly stepped out of the storeroom, moving a bit faster than usual.

"Hey, Yuzuno," Sanae said slowly as she watched the captain’s back.

"Did you see the midterm exam results?"

"The exam? Yeah. Well, fine, not so fine, just like that."

"Not your individual score. I mean the ranking."

Kazeno Hill High School prided itself on its high rate of advancement, and after every exam, the names and scores of high-achieving students were ranked and posted on the bulletin board at the entrance. Today in the morning, the comprehensive results of the midterm exam held three weeks ago were announced.

Of course, Yuzuno knew about this. However, this didn’t concern her scores just a few points around the average, so she didn’t particularly pay attention.

"I haven’t checked. Sanae, don’t tell me you made the list?"

"Silly, how could I? Sugawa made it to the list."

"Ah…"

Yuzuno, who was about to pull out a folding table, suddenly stopped in her tracks.

"No way? The captain made the list?"

"It’s true, it’s true. She was sixth place in the entire second-year!"

In nearly three hundred second-year students, she had achieved the impressive feat of placing sixth...

"I always thought she was smart, but this is incredible!"

"Right, right! She seems only to be wholeheartedly committed to her club activities. Sugawa is really outstanding!"

"Yeah… I want to be like her!"

That was Yuzuno's heartfelt thought.

They had to add another title to the captain—"brilliant in literature and martial arts." No, calling her "perfect superhuman" would be easier to understand.

"Hey, hurry up!" A voice from outside the storage room urged them on—the voice of their perfect superhuman. Yuzuno and her companions hurriedly carried the table out of the storeroom. Two male badminton players, who had somehow arrived at the gym, passed by them into the storeroom.

"Speaking of exam scores…"

As they pushed the table to its fixed position, Sanae continued.

"It wasn’t just Sugawa’s achievement that was impressive. I was really taken aback by the ranks of other second-year students."

"What happened?"

"Someone scored nine hundred points in total!"

"…Nine hundred points?"

It took Yuzuno a moment to grasp Sanae’s meaning.

Midterm rankings, for any grade, should have been based on the total score of nine subjects. Scoring nine hundred points means that this person:

"Got a full score in every subject?"

"Exactly, exactly!"

Heavens, what kind of detached-from-reality grade is that!

"Who is it? Is it Masaki?"

In Yuzuno’s mind, she conjured the image of Akihiro Masaki, the newly elected student council president from the previous month.

The student council elections held in early May were fervent events, unlike the pro forma ones in junior high. The position was extremely important for seniors aiming for university recommendations, and several candidates fiercely competed, leaving a deep impression on Yuzuno. Ultimately, Akihiro Masaki, a second-year student, won by a narrow margin. He was an honor student active in the student council since his first year, and it would be convincing if he were the one with a perfect score. Besides, he was quite popular among the girls.

However, Sanae shook her head and said:

"Unfortunately, the president scored 870 and was second. Although that’s also remarkable, he couldn’t beat the full score."

"Then, who could it be? Vice President Yatsuhashi?"

"Hehe, too bad. Yatsuhashi came third. The top scorer was someone I’d never heard of. Some 'Inside' something or other… a person with a weird name."

"Inside…?"

This name was entirely new to her. It was natural that she hadn’t heard of this person before, given that Yuzuno and Sanae, as first-year students, had limited acquaintances among the second-year students outside their table tennis club seniors.

"And there’s a particularly strange rumor about this 'Inside' person."

As they set up the first table and returned to the storeroom to fetch the second, Sanae hadn’t finished speaking.

"It’s said that he lives in the activity rooms."

"Huh?"

Yuzuno was stuck in a loop of reacting with surprise.

"In the cultural club’s activity building, there’s an 'unopenable room,' right? On the far west side on the first floor, there’s a room that’s always locked."

"Isn’t that just a room that’s not used?"

"Yes, it is. But they say he’s living in that 'unopenable room,' or perhaps not..."

"What do you mean by that?"

The conversation was swaying from midterm exam discussion to campus's seven unsolved mysteries.

"Ha, haha, looking at your expression, you don’t believe it, right?"

"Of course I don’t! Who could possibly live in an activity room?"

"It's true, it's true. Almost no teachers or students notice. I heard it from Koike from the school newspaper. He said he heard it from the newspaper club president..."

"Isn't that still hearsay?"

"What about the teacher?"

Masumura, who was checking the training plan, showed interest in their conversation. Sanae hastily averted the topic:

"Ah, nothing. We were saying how handsome you look today, sir."

"Ha, is that so? Kinda flattering, aren’t you?"

Masumura's words were accompanied by scratching his close-cropped hair bashfully. Such a pure-hearted man.

"You want me to go easy during practice, well, I can’t do that! Summer’s just around the corner, and we’ll be stepping up today!"

"No, we didn’t mean that… Does that mean practice will be stricter? Oh, not looking forward to it."

"No complaints!"

Captain Sugawa interjected.

"Starting today, we'll double the smashes in the drive group; you can’t win without attack power. For the chop group, using the ball machine..."

And at that moment.

Thud—thud—

A drum-like sound reverberated from an unknown location.

Although the sound was indistinct, it was quite loud. Everyone in the gym stopped moving. In the gym filled with echoes, the lingering sound seemed a bit eerie.

"…What’s that noise?"

It took a moment before Masumura finally responded.

"Is it thunder?"

"I don’t think so," the captain disagreed with Sanae’s opinion. "It feels more rhythmic… could the wind ensemble be rehearsing?"

"Eh? The music room is in the second teaching building. It shouldn’t reach here..."

"Sorry to interrupt!"

Another sudden loud voice, this time from a person. A disheveled male student stuck his head out from the side entrance of the stage—it was drama club leader Kazuya Kajiwara.

"Did you lower the stage curtain?!"

Yuzuno and Sanae exchanged glances and shook their heads. The curtain was already down when they arrived.

"Oh, maybe Asaijima lowered it," Captain Sugawa, who had been at the gym since three o’clock, replied. Asaijima was the broadcasting station head and a third-year student that Yuzuno was well acquainted with.

"A while ago, he got on stage from the side, and right then the curtain came down. Right, Mr. Masumura?"

She confirmed with Masumura, who nodded affirmatively.

"Huh? Asaijima lowered it? Why?"

"This I don’t know."

"That's strange... Nevermind. Hey, Sanjo, raise the curtain!"

Kajiwara tilted his head lightly in puzzlement, then instructed someone inside the doorway.

Subsequently, a member of the drama club who was standing by the side of the stage operated the electrical curtain machine. With the machine’s subdued rumble, the curtain began to rise toward the ceiling.

Kajiwara’s arrival captured the attention of Yuzuno and others, and they couldn’t help but watch the scene unfolding on the stage dazedly.

Then, “Ah…?”

They realized something unusual.

The slowly revealing stage. The podium placed at the center.

Beside the podium, which the principal and grade group leaders always used for making boring speeches, leaned someone.
A boy wearing the school's standard navy blue vest had his head drooping lifelessly. His shoulders were also limp, giving the impression that he was asleep. Sleeping in a place like this? Wait a minute, there seemed to be something sticking out of his chest. That thing... that thing was just like—

A slender knife. The silver blade made the blood appear even more scarlet.

"......"

No one could comprehend the scene before them. Yuzuno, Sanae, the captain of the table tennis team, and even Masumura couldn't understand it.

Kajiwara, who hadn't noticed the unusual situation on stage, poked his head out from the side of the stage after the curtain rose and finally saw the scene:

"Huh? What's going on... Asajima?"

A puzzled voice. And then, the piercing screams that everyone let out simultaneously. Yuzuno realized it was her own voice, perhaps after all this happened.

---

2 The Capable Detective and the Melancholic Detective

Detective Yusaku Hakata of the Kanagawa Prefectural Police's investigation division got out of the car, looked up at the white school building in front of him, and sighed wearily.

"What's the matter?" Chief Sendou asked. "Nothing," Hakata answered dismissively. It wasn't his obligation to report every personal issue to his superior.

"A case at a school must be challenging, I understand your sigh," Sendou said.

"Indeed..." Hakata's concerns were somewhat different, but he broadly agreed with Sendou's sentiment.

A murder case occurring in a high school gymnasium, with details still unclear, was bound to make the investigation bothersome. Moreover, he foresaw media coverage and had a growing sense of foreboding due to his personal circumstances.

"Ah, it's over there."

With the curious students gathered noisily, there was no need to search; it was easy to determine the direction of the crime scene. Following the students to the back of the school building brought them to an old gymnasium with peeling paint on the outer walls.

"There are so many students here; I heard they already sent away unrelated personnel."

"If it were still raining, there would be fewer people."

Sendou glanced at the sky, glaring at the rain that had inconveniently stopped. The downpour that lasted until around four in the afternoon had completely subsided, leaving only thin clouds in the sky. The cheerful weather forecaster on the morning news had said the rain might continue until nine in the evening, proving the forecast unreliable.

Navigating through the students, they finally reached the familiar yellow tape marked "KEEP OUT." A police officer was desperately trying to calm the crowd of students. They presented their police IDs and entered the area cordoned off by the yellow tape.

"Hello! Could you tell us what's happened here?"

At the precise moment they crossed the boundary, a girl with glasses asked. It was exhausting to entertain every individual, so they ignored her. A DSLR camera hung from her neck, putting actual media personnel to shame - she was probably with the school newspaper.

Later, the girl shouted at the police in charge of security:

"You should tell us what's going on! This happened at our school! We have the right to know! The right to know!"

Teenagers, such a headache... Hakata couldn't help but smile wryly. Then, he realized that this was indeed "Kazeoka High School," plunging him back into melancholy.

They entered the gym through the hallway doors, greeted by a nostalgic scent of wood, sweat, and leather from balls. This was his first visit to the school gym since graduation. Although Hakata hadn't graduated from this particular high school, the structure of this building was fundamentally the same as the "gymnasium" he was familiar with, evoking nostalgia.

In front of them lay a slightly polished wooden floor, stretching into the distance with lines in different colors. An iron walkway, rusting all over, lined the wall on the second floor. To the left was a large stage elevated above the rest. Most of the investigators moved back and forth on the stage. It seemed like the actual site of the incident was on the stage.

There were doors leading to side stages on both sides of the main stage. Above the door on the left was a small window on the second floor, possibly a control room for adjusting stage equipment like audio. Above the right door was no window, but a wooden plaque engraved with the school song lyrics and a clock hung in that spot.

Hakata compared the time on his wristwatch with the clock, confirming the time. It was 5:04 PM. Both the watch and the clock were accurate.

"Let's have a look."

Sendou headed straight to the stage. Hakata followed him. He hesitated for a moment about stepping onto the gym floor in shoes but realized the urgency of the situation left no room for such concerns.

"Ah, hello! You're from the Prefectural Police, right?"

A slightly aged man in a crumpled old suit noticed them and descended a short staircase from the stage. Hakata and Sendou nodded in greeting.

"I'm Detective Sendou, and this is my subordinate Hakata."

"Hello, hello! I'm Shirato, the chief inspector of the Hodono Valley Police Station," introduced the detective, Shirato, repeatedly bowing as he greeted them. He seemed to be around fifty-five to sixty years old, looking about five or six years older than Sendou, and even older relative to Hakata.

"I heard there was a murder."

"Yes, yes, over here. Please."

Shirato, with a warm, friendly face reminiscent of a Maitreya Buddha, nodded and led the two to the stage. He didn't seem to mind the rivalry between the station and the Prefectural Police or the age difference between them. Hakata felt temporarily relieved. As a 25-year-old newcomer, he often wasn't taken seriously on the front lines filled with veteran detectives.

With the thin curtain beside the podium pulled aside, the body was revealed.

The corpse leaned against the side of the podium, legs sprawled on the floor, with the upper body slightly tilted, the left shoulder lower and the right shoulder higher.

The scene wasn't horrific. Apart from the slender knife in the chest, the flowing blood, and the pale face, there wasn't much difference from how a person looked alive. The boy's bangs were neatly trimmed, giving him a serious appearance. His facial expression was relatively calm. The badge attached to the navy vest cruelly emphasized that he was a student of this school.

"What's this child's name?"

After a moment of silence, Sendou asked. "His name is Tomoki Asajima, a third-year student from Class 2. It's said he's the head of the broadcasting station."

Shirato relayed the information he had memorized, and Hakata noted it in his beloved notebook.

"He had his student ID in his pocket, and we've confirmed his identity with the teacher who found him. There's no mistake."

"What was the cause of death? Is it that thing in the chest?"

"Yes. We were just discussing it... Doctor, please."

The man in a white coat stepped forward. While Shirato gave off a warm, round impression, this doctor had a square silhouette from his physique to his shoulders. Speaking in a stiff tone, he introduced himself as "Forensic Doctor Yumihasa."

"The cause of death is the knife wound to the chest, no doubt there are no other injuries. Of course, if he was poisoned, that would be another matter."

"I see. Was it instantaneous death? From the body, it doesn't seem he suffered."

"Almost immediate death, stabbed directly in the heart. If done by a kid, that's remarkable."

Yumihasa snorted through his nose, as if mocking the culprit who accomplished the feat with one stab.

"You think the culprit is a kid?"

"I don't know. But a murder occurring in a place like this surely must be done by a student, right?"

"Oh, I see what you mean."

"I suppose we're not mistaken. The video cameras at the main entrance and the north entrance didn't capture any suspicious individuals coming or going, nor has there been any report of suspicious persons on campus."

Shirato interjected.

"...Hmm, even if we can't outright say the culprit was a student, the possibility of them being school-related personnel is high. You're correct since the crime occurred in a place like this."

Sendou looked up at the high ceilings of the gym once more before turning his head to observe the victim again. The left half of the vest was blackened by the flowing blood, the source from the murder weapon that still glimmered with a silver glow.

"Where did the knife come from?"

"It seems to be a commercially available camping product, but the specifics aren't clear yet. There are no fingerprints on it."

"No fingerprints... It is indeed murder. Yumihasa, what's your estimated time of death?"

"There are minor lividity marks, but the boundaries remain clear, with the body showing slight rigor mortis. Estimated time of death is around two hours ago."

"It's just past 5 PM now, which means he died around 3 PM."

"Indeed."

"It matches the witness testimonies too."

Shirato still wore that Buddha-like expression, as if implying an underlying meaning.

"...This aspect we'll have to investigate further. Have the belongings been collected? Then let's send the body to Forensics. Please also examine the murder weapon."

Following the instructions, the body was taken out on a prepared stretcher. Yumihasa also left. Thus, the protagonist of the case—the victim—disappeared from the stage.

At this point, another object caught Hakata's attention.

"...Excuse me, Detective Shirato, what is that?"

"That, as you can see, is a bloodstain."

"Bloodstain..."

On the floor, to the viewer's right when facing the stage wall—to the right from the audience's perspective—remained a line of dark droplets of blood.

This blood trail started from behind the curtain that separated the stage and the right side stage and stretched straight to the white tape marked for the victim's discovery.

"The body was dragged here after being stabbed there. So the actual crime scene is over here."

Shirato headed towards the right of the stage, stepped into the darkness formed by the two side curtains. On the floor lay a pool of blood.

"Figured as much." Sendou agreed, standing beside Hakata.

"I was wondering why there was so little blood if he was stabbed directly in the heart. Turns out it all pooled here."

"Indeed, but the knife acted as a plug, preventing blood from splattering. See, there's no spatter on the ground."

"Oh, is that so. It does seem like skilled work."

"This is the scene... Then, the murderer moved the body after killing?"

Why move it?

The thought came to Hakata, but he quickly dismissed it: Hold on!

There isn't enough information for the brain to work. Reasoning with a brain lacking sufficient information is more likely to fall into traps.

Therefore, my current job is to take notes first and gather information. This was the teaching of Sendou, and Hakata believed it was a correct approach. Up until now, he and this competent detective have solved cases successfully this way—that's self-evident.

By collecting factual evidence one piece at a time, without doing unnecessary work, you can discern clues. And those clues must be the truth.

"Let's gather information!"

Perhaps in sync with Hakata's thoughts, Sendou urged Shirato, looking to gain more clues.

"Alright, I've arranged for those involved at the scene at the time to wait in a nearby vacant classroom. Shall we go there, or call them here?"

"Could you please call them here one by one? Given the size of this building, it would be more convenient to have them explain directly here."

"Understood."

"Oh, the people you're referring to...?"

Trying to appear nonchalant, Hakata asked.

"There's a male teacher, and the rest are students. Members of both the drama club and the table tennis team, among others."

"Table, table tennis..."

Hearing this word that frightened him, Hakata couldn't help but shrink back.

"Uh? What's wrong?"

"Nothing, nothing at all. It's fine."

Hakata convinced himself—it's probably not what I fear, no need to worry.

Shirato, the chief inspector of Hodono Valley Police Station, looked at him doubtfully, but soon forgot, having a brief conversation with the nearby search crew. Then, he turned back with that same Maitreya Buddha-like smile.

"I've asked for the list of involved individuals and the victim's belongings to be brought over."

"Thanks... Regarding what you mentioned earlier..."

Sendou nudged his subordinate gently—Hakata, who was busy reassuring himself, "It's fine, it's fine"—clearly reminding him to take notes. Hakata snapped out of it and quickly prepared to jot down.

"What you mentioned earlier, what did you mean by that?"

"Oh... actually, there's nothing significant about it, and it might be my mistake."

"After you said that, my curiosity is piqued. Is there something suspicious about the case?"

"No, it's really nothing."

Shirato idly scratched his sparse white hair. Having previously worked in the organized crime countermeasures division, Sendou's gaze became more intense.

The chief inspector, resignedly, began:

"The first person to arrive at the scene was Tsuchiya, stationed at the booth directly behind this high school. He protected the crime scene and quickly inquired, managing to extract a peculiar testimony."

"Really? What kind of testimony?"

"At the time of the incident, the stage of this gymnasium... was a sealed room!"

"A sealed room?"

Known for his composure, even the inspector couldn't help but exclaim this time.

"Indeed. All entries and exits were either locked or under guard."

A sealed room. Although prompted to take notes, Hakata hesitated, uncertain whether to jot down these two words.

In this huge stage, at the time of the incident, was it a sealed room?

However—

"But it's undoubtedly murder, right? No fingerprints on the knife, and the victim was dragged over five meters."

Hakata confirmed, and Shirato nodded deeply in agreement.

"Yes, indeed, it's definitely homicide. Yet, at that time, it was a sealed room. Strange, isn't it?"

This round-faced detective laughed heartily, clearly intrigued. Then noticing the awkwardness around him, he suddenly realized and clapped his hands saying:

"Oh right, you'll need chairs for the questioning here, won't you? I'll go and fetch some!"

This time, instead of delegating the task to subordinates, he descended from the stage and exited the gym.

It seemed he wasn't willing to be interrogated further.

"Sendou, about what Shirato just mentioned..."

Once it was just the two of them, Hakata asked for his superior's opinion. Sendou pursed his lips tightly.

"It's hard to judge without understanding the actual situation... perhaps, as Shirato said, it's a misunderstanding."

"Yes, it is."

"Obviously. Otherwise..."

Sendou left the sentence hanging, but Hakata easily imagined the conclusion.

Otherwise—it's a sealed room murder.

This was unimaginable, something he didn't want to imagine. A murder case occurring at a high school, and in Kazeoka High School, within the gym, somehow related to the table tennis team! Just these facts were overwhelming! To add to it—an impossible crime?

Sigh.

Hakata sighed again.

He felt a bit of stomach ache.

---

3 The Unsolved Marker is Red and Black

Soon, a search officer arrived with the list of involved individuals and the victim’s belongings. The belongings weren't much, merely some miscellaneous items on a tray. Meanwhile, Shirato struggled back with three steel-framed folding chairs.

Sendou glanced at the list of people involved first. Although Hakata wanted a peek, unfortunately, the detective folded the paper into quarters and tucked it into his pocket.

"Well then, please call in the first person who discovered the body—Teacher Masumura."
"Sendo briefly issued instructions and then turned his attention to the victim's personal belongings on the tray. Hakata, meanwhile, was both frustrated and anxious for not having seen the list, and began taking notes one by one.

A packet of portable tissues stained with blood. A similarly blood-stained student handbook. A wallet, a mobile phone, a keychain. And a DVD in a thin, transparent sleeve. The surface of the disc was green, with no title written on it.

“Except for the student handbook, everything else was in the pants pockets. The tissues were in the left pocket, the wallet and phone in the right pocket, and the DVD in the back right pocket. The student handbook was found in the shirt’s left breast pocket,” said Shirato, patting his own pockets as he explained. Ah, I see, the blood on the tissues and the student handbook was because they were in the pocket on the left side of the body where the blood flowed.

“What are these keys for?” Sendo swiftly picked up the keychain with his gloved hand. There were three keys, each hanging on a slightly old-fashioned Nikko Three Monkeys keychain, labeled “See No Evil, Speak No Evil, Hear No Evil,” with no indication of which rooms the keys corresponded to.

“It turns out these are keys to the broadcasting rooms. ‘See No Evil’ is for the broadcast room in the main school building. ‘Speak No Evil’ is for the new gym broadcast room behind the school building. ‘Hear No Evil’ is the key to the old gym broadcast room, which is right here.”

“Oh, you mentioned earlier that he was the head of the broadcasting station. The broadcast room is over there, right?” Sendo pointed to the small room on the second floor at the left side of the stage—opposite the audience. Shirato nodded, “Exactly.”

“We checked the broadcast room, but didn’t find anything special.”

“What about this DVD? Is it related to the broadcast station?”

“Yes. We’ve already confirmed that the footage on it is ‘Introducing Kaze Hill High School,’ something like a promotional video. It might have been shot by the kids at the broadcast station.”

“And it was kept by the station head... What about this?” He picked up the blackened student handbook next.

“It’s soaked in blood.”

“Well, it was right against the wound after all. The victim wrote a lot of plans in the handbook, and I was hoping the plan for today might have been written there...”

Sendo took the handbook out of the plastic bag and flipped it open. However, the record grids were entirely covered with the owner’s bloodstains, and the writing was indistinct, making it impossible even to find where today’s plan was written.

“...Let’s leave this to the forensic department.” Sendo returned the student handbook to the tray and asked, “Are these all the found items?”

“There are actually a few things on the side stage that are of concern... a necktie and an umbrella.”

“A necktie? An umbrella?”

“I’ll show you while introducing the scene. It’s over here.”

Completely assuming the role of a guide, Shirato swung his hand wide and led the two onto the stage. After passing behind the side curtain and stepping down four steps, they reached the dimly lit side stage.

Being a gymnasium, the side stage wasn’t very large. To the left was a long staircase leading to the second floor, and there were seemingly heavy doors on the front and right walls. In front of the door on the front, a green doormat was laid out.

Hakata thought that judging by its position, the door on the right must connect to the inside, while the front door connected to the outside. Shirato indeed confirmed this to be true.

“This is the entrance to the outside, usually locked from the inside.”

“Oh.”

Sendo and Hakata observed carefully in the dim light and found the lock. It was a common cylindrical lock that could be locked from the inside by turning a small handle. Sendo tried it, and by turning the handle, opened the door leading to the back of the gymnasium. It seemed this was the very edge of the campus, with nothing but trees and a person-high fence. Not even a shadow of a person was visible on the narrow path outside the fence. However, heading a little left along the fence, there was what seemed to be a small rear gate.

“What’s that?”

“I heard it’s the rear gate. This school has three gates: the main gate, the north gate, and the rear gate. The rear gate is so small that no cameras were installed there.”

Sendo listened to Shirato as he introduced the campus while moving to the back of the gymnasium and approaching this small gate. The ground was covered with neglected wild grass, and near the rear gate, a patch of bare earth was exposed. Due to the rain, the ground was muddy, with what seemed to be two lines of footprints leading to and from this spot. However, the footprints weren’t clear enough to determine what kind of shoes had made them.

“There are footprints on the ground. Does this gate usually get a lot of traffic?”

“Quite the opposite. This is truly a rear gate, seldom used by teachers or students.”

“So, it’s possible someone unrelated to the school might have entered the campus through here.”

The inspector returned inside the gymnasium, closed the door, and locked it again. Then, after wiping the mud off his shoes on the mat, he suddenly asked:

“What was the state of this lock at the time of the incident? I mean, when the incident occurred.”

“Ah... the door was locked. Well, that’s another mystery.”

Shirato chuckled somewhat casually, motioning with his chin to the wall beside the stage.

“Well, back to the topics, this is the necktie.”

Behind the stairs leading to the second floor, there was a hand-drawn poster on a large sheet of paper. Upon closer inspection, it was written with a permanent marker to say “59th Cultural Festival.” This poster must have been used at some school-wide meeting and left untouched here since.

There was a scattered red necktie on the poster.

“A necktie... Looks like something from a student’s uniform.”

“Yes. I’ve heard that in this school, boys wear ties, and girls wear neck ribbons.”

“Is this necktie from the school uniform?”

“It likely is, possibly belonging to some student.”

Hakata recalled the students from Kaze Hill gathered in front of the gym. The neck ribbons on the girls’ school uniform shirts were indeed bowknot-shaped.

Sendo crouched and picked up the necktie. The necktie was clean and unscrambled, not looking freshly taken off from someone.

A plain red necktie with nothing special about it.

“We took photographs when we first found it. Hmm... Ah, here it is.” Shirato pulled a printed photo from his chest pocket. The scene depicted was the same as what lay before them, showing a dry poster with a necktie on it, yielding nothing worth noting.

“Does this have any relation to the case?” asked Hakata abruptly. He couldn’t see how it might. Shirato shrugged, saying, “I wouldn’t know... but a janitor who cleaned the gym after lunch said he didn’t see this thing. The related personnel also said they don’t know. However, some testified seeing a girl enter backstage. So, perhaps the necktie has something to do with the case.”

He used the word “however” again, Hakata noted in his mind.

“Where is that umbrella mentioned before?”

“It’s on the left side facing the audience.”

Hakata and the others returned to the stage, led by Shirato across to the other side.

The opposite side stage was almost identical to the one on the right. The ceiling seemed lower here due to the radio room protruding on the second floor.

There was one more difference. The right front door was made of iron, while this one was made of wood, scarred and appearing cheap. There was no knob on the door handle, and it seemed not to have a lock.

He quickly realized why. Shirato opened the door to reveal, not the outside, but rather another dark corridor, with frosted glass doors to a women’s restroom and a men’s restroom lined up from right to left.

“As you can see, this side stage is wider since it has restrooms.”

Sendo and Hakata, following Shirato through the wooden door, saw the corridor extending left about three meters before turning right. Slightly ahead was another entrance connecting to the outside. This door wasn’t iron either, but appeared stylish and elegant, a glass double door. Through the glass, they could see the white school building opposite.

In front of the door was a small cemented area, with four umbrellas lined against the wall.

“About the umbrella you mentioned...”

“Oh, not those. The umbrellas and the shoes on the cement are the belongings of the drama club members who first discovered the body.” Hakata wanted to ask, “Are those the umbrellas?” but before he could finish, Shirato answered preemptively.

“I am referring to the umbrella found in the men’s restroom... over here.”

The three entered the men’s restroom. It was precisely what you would expect of an old gymnasium. The stains on the tiles clearly indicated this was an aged restroom.

Shirato pointed towards the couple of stalls, specifically the farther one with a squat toilet, a silver handle, and protruding pipes, as well as a toilet paper holder on the wall. The floor inside the stall was wet due to excessive flushing and other usual reasons, as is common with this type of restroom.

There, on the tiles, lay a closed black gentleman’s umbrella. 

The umbrella was long, the type used by businessmen, appearing high-quality. The inspector picked up the umbrella, examined it from top to bottom, untied it, pressed the one-touch button, and opened it. Faint branding visible on the fabric indicated it was a business brand Hakata recognized. There were no holes, and the frame was undamaged, looking like new. If any flaw had to be mentioned, it was just a two-centimeter scratch on the tip of the handle.

“They say it was soaking in water from the start, thoroughly wet,” Shirato said, pulling another photo, taken when the umbrella was found, from his chest. The scene was as it appeared now.

“Is this Asajima’s?” 

“No, it isn’t. I hear his umbrella and belongings are still in his classroom, and witnesses say he was empty-handed.”

“Whose umbrella is it then...?”

“We don’t know yet. The umbrella was soaked completely, including the tip of the handle, so no fingerprints could be identified. Like the necktie, we had relevant personnel confirm it wasn’t theirs, and none owned it. However, the aforementioned janitor testified that he hadn’t seen the umbrella by the end of the lunch break. Oh, the janitor has a solid alibi.”

“A fingerprintless, soaked umbrella...”

Sendo crossed his arms over his chest, lost in thought. After a while, he turned to Hakata, who gleefully showed him his notebook, indicating everything was noted down. The notebook was densely filled with information about these inexplicable remnants. Pleased, the inspector nodded and said:

“Let’s head back. Masumura-sensei should be arriving soon.”

The inspector, proud of his words, turned energetically back around.

Hakata found such a boss reliable. Though understanding the full outline of the case was yet unclear, the data surely was becoming more comprehensive.

— No worries. 

Whether it concerns the case or personal matters.

Masumura was waiting with the investigation personnel near the gym entrance. Young, with a crew cut, he wore a black-striped white tracksuit and had a sturdy build. While a vigorous smile might have suited him, his current expression was tense and stiff.

Chairs set before the stage, the prefectural police’s detectives and the high school teacher sat face to face.

In this overly open and unusual interrogation room, they began their questioning.

4 A Girl Running on the Verge

“Your name?”

“Shintaro Masumura. I teach physics and chemistry at this high school and am the advisor and coach of the girls’ table tennis team.”

“Gi-Girls’ Table Tennis Team?”

Barely four seconds into the questioning, Hakata realized that his confident assertion of “No worries” was vehemently shaken. The case indeed involved the girls’ table tennis team.

“Hakata? What’s up?” 

“Nothing. Please, go on.”

“Well then, Masumura-san, you were one of the first to discover Asajima’s body, is that correct?”

“Yes... I was in this building at the time,”

“Can you recount the circumstances of discovering the body? Start from when you first arrived here. You may have already told the local police, but we need you to recount it again.”

“Sure. Um, I arrived at the gymnasium at exactly three o’clock, coinciding with the end of class.”

“Do you usually come at this time?”

“No, normally it’s later. Today, I didn’t have a sixth period, so I could come earlier.”

Contrary to Sendou’s sharp eyes, his demeanor was cordial. Perhaps this attitude helped Masumura to relax; he gradually loosened up.

“You’re certain you arrived at three o’clock precisely?”

“Yes. I remember hearing the class bell, and the team member Sugawa who accompanied me said, ‘Right on three.’”

“Did you come with a student?”

“Yes. I was heading here from the office and met her on the way. I wondered why she was so early since there was still class time left. She told me her class recessed about ten minutes early.”

“That’s indeed the case. I’ve confirmed with the office that only second-year class four had an early dismissal.”

Whispered Shirato, standing next to Sendo.

“The class dismissed early can leave the classroom right away?”

“We don’t typically hold homeroom sessions until after final dismissal.”

“I see... So, to return to the sequence of events, when you entered the gymnasium, was there anyone inside?”

“To my knowledge, no one. There were no classes or activity scheduled during sixth period here today.”

“Did you enter through the door that leads to the corridor?”

Sendo pointed to the door through which he had come. Masumura replied, “Of course, through this door,”

“Since it was raining, Sugawa and I entered through this door.”

“I see... You mentioned initially that there was no one in the gym, was this door locked?”

“It wasn’t locked. The corridor’s door typically stays open during class and club activities. The other doors, however, were locked.”

“It wasn’t locked. So what did you do upon entering the gym at three?”

“I did some stretching exercises with Sugawa against the wall. Then, after about three minutes, Asajima entered the gym from the corridor’s door.”

Masumura’s face momentarily distorted when mentioning the deceased’s name.

“So around 3:03 PM. What did he do next?”

“Well, he passed by the storage at that end and immediately entered the side door, I wasn’t sure what he was here to do... I assumed he might have some business in the broadcast room,” 

Masumura pointed at the door leading to the left side stage, facing the audience.

“Oh, but right after that, the stage curtain was lowered. I found it a bit odd to see Asajima from the broadcast station lowering the curtain.”

“The curtain was lowered. Was it done by Asajima?”

“I didn’t directly see him operate the machine, so I can’t be sure... Anyway, the curtain was down just as he entered the backstage.”

“Hmm.”

Sendo rested his hand on his chin, deep in thought, while Hakata earnestly continued making notes.

“Before the curtain came down, did anything catch your attention on the stage?”

“I didn’t scrutinize it, but I think there wasn’t anything unusual.”

“For instance, the lighting? The lights were on when we arrived.”

“At the start, the lights weren’t on. They were probably turned on by him after lowering the curtain. The lights can also be controlled by the switch on the left side of the stage.”

“So he had some business on the stage.”

Sendo murmured.

“At the time, was there anything peculiar about Asajima’s demeanor?”

“Not that I noticed. He was only in my line of sight for an instant... But I’m certain he was empty-handed, without any belongings.”

“I understand, and then, Asajima disappeared from view. Meaning... until his body was discovered.”

“Yes. However, around 3:05 PM to 3:10 PM I left for the office.”

“Return to the office? Why was that?”

“I forgot the club practice schedule sheet in my office, so I went back to retrieve it.”

“This was also verified with the office. Masumura-sensei returned to the office around 3:08 PM and promptly left thereafter.”

Whispered Shirato once again.

“During that time, the gymnasium...”

“I believe Sugawa was the only one there. Oh, no, perhaps Asajima was still backstage.”

“What was it like when you returned from the office to the gymnasium?”

“There was no change.”
Nao Sugawa was still doing stretches. I stood with her and began warming up my body, then two more members of the table tennis team came in.

Masumura blandly recounted the next steps. The team members started preparing for practice as usual. Meanwhile, the students from the badminton team began their preparations in the gym too. Then around 3:15, everyone heard sounds like drums.

"Drums?"

"Yeah. I couldn't quite tell what it was exactly, but I heard a 'thud thud thud' sound. Then Kajiwara from the drama club came out of the door Asajima had entered from and asked who had lowered the curtain."

"Ah, wait. Where did that student enter the gym from?"

"The drama club students always enter through the door on the left side."

"The side with the bathroom, right? Oh, that's why there was an umbrella at the entrance."

"Yes. It's close to the stage, making it convenient for carrying props for plays, and so on... Then Sugawa said it was Asajima who lowered it, and Kajiwara just said, 'Alright, alright, let's just raise it.' So the other drama club members lifted the curtain..."

"And then they discovered Asajima had died on the stage."

Masumura lowered his gaze and nodded silently.

"What did you do after the body was discovered?"

"I approached the stage... Once I confirmed he was dead, I asked the boys from the badminton team to go to the office for help and gathered the other students to one place to wait quietly. A couple of students peeked into the gym at the sound of screams, and worried they might cause trouble, I immediately let them in as well. That's how it was. The officers from Hodogaya Police Department instructed us, no one to touch the body directly. I didn't touch it either."

"That's a wise decision."

"No, to be honest, I was just too scared to touch it... Anyway, the police arrived in about five minutes. After that, the gym was sealed off, and it remains so even now."

Masumura finished speaking. Sendou pondered for a moment before asking a question:

"When you were in the gym, did you see anyone come out from backstage? Other than the drama club students."

Masumura furrowed his brows, seeming to search his memory, then shook his head and said:

"No, not a single person came out."

"Understood. Thank you very much!"

"Which means, Asajima Tomoki was likely killed between 3:03 and 3:15."

After returning to the waiting classroom, Hakata reread his notes and summarized his testimony.

"I see. However, what I'm concerned about is the curtain was dropped right after Asajima entered backstage. And then there's the drum sound."

"…Well, putting aside the drum sound for now, what was Asajima planning to do backstage? Why would the head of the broadcasting station lower the curtain?"

"Still unclear… still unclear."

Having more or less grasped the situation's outline, Sendou's eyes seemed to shine brighter. He swiftly turned around, instructing Shirato standing behind him:

"Then next, please bring in the girl Sagawa who came to the gym with Masumura."

Shirato seemed to have anticipated Sendou's thoughts and had already sent someone to fetch her. The girl soon walked into the gym.

She was a noticeably pretty girl wearing the blue practice uniform of the table tennis team. Though a girl, she was tall and spirited, well-suited to her short hair. However, faced with such a shocking case, her expression was somewhat gloomy. Her bright eyes stayed fixed on the stage where the body had just been lying, until she sat down on a chair.

"Hello!"

Sendou's manner was even more gentle than it was with Masumura.

"I'm Sendou of the Kanagawa Prefectural Police, and this is my subordinate Hakata."

"Ah, oh… hello!"

Perhaps due to fear or nervousness, or maybe both, her response was a bit vague.

"Please tell me your name and what year you're in first."

"Um, my name is Nao Sugawa. I'm in class 4, second-year, student number 18, and I'm the captain of the girls' table tennis team."

"You're already the captain in your second year? That's impressive!"

"No, it's not. A third-year student retired about a month ago, so I'm just..."

"Oh, I see. Still, becoming captain is a big deal."

"Not really… thank you."

Nao Sugawa did not look at Sendou during their conversation but kept staring at Hakata. What was going on? Did Hakata have something on his face?

"By the way, you came with Masumura-sensei, right?"

When Sendou's questioning got to the point, Nao finally moved her gaze away from Hakata.

"Yes. Because class ended early, I changed in the activity room and planned on heading to the gym... I met Masumura-sensei on the way, so we came in together. It was precisely three o'clock."

"Are you sure it was exactly three o'clock? And then?"

"Just the two of us, sensei and I, were stretching over there."

She pointed to a corner by the wall, directly opposite from the door leading from the corridor. There were three sets of racket covers, mineral water bottles, and shoe bags laid out nearby, presumably belonging to her and the two members who arrived at the gym later.

"After two or three minutes, Asajima came in and immediately went into the left-side wing. I assumed he had business in the broadcast room over there and didn't pay much attention, but then the curtain on stage came down right after…"

"You're sure it was Asajima who went into the left-side wing?"

"Yes, I'm well-acquainted with Asajima, so I wouldn't mistake it."

"Do you remember what he looked like at the time? Was he carrying anything?"

"Um… he was a bit far away, so I couldn't see his exact appearance, but I think he wasn't holding anything… oh, right, he wasn't wearing sneakers. And, oh, he came in wearing slippers. But I thought, since he's not exercising anyway, it doesn't matter."

As expected of the table tennis team captain who uses the gym as her base, her observations were so meticulous.

Hakata turned back a few pages in his notebook for a simple verification. Up till now, her testimony matched Masumura's exactly. The problem lay beyond that point.

"And Masumura-sensei went back to the office at 3:05?"

"Yes."

"You were alone here at that time, weren't you? From 3:05 to 3:10."

—Yes, I was here doing stretches alone, as expected.

Just as it was anticipated she'd say. But—

"No."

The result was completely opposite.

Nao Sugawa, who had been slightly lowering her head, suddenly raised it and clearly testified:

"A girl came in from the corridor. She was wearing a uniform and empty-handed, and she went directly into the left-side wing."

"What?"

Even Sendou, who had been staring sharply at the girl, was surprised and widened his eyes.

Oh my, oh my—Shirato smiled and shrugged. It reminded me of something he mentioned earlier—

Someone did testify to seeing a girl walk backstage.

Yes! Shirato had used "someone" the second time then.

It seems this smiling detective has a nice side, a good-natured curiosity. Even if it pertains to the case, he pretends not to mention troublesome topics and takes pleasure in it.

Which means, this testimony might be categorized as "troublesome."

"…What was the girl like? Do you know her?"

After controlling his surprise, Sendou pressed on. Nao Sugawa thought for a bit before saying:

"I can't say for sure. Feels like I've seen her somewhere, but her face was covered by her hair, and she ran by quickly from the side, so I can't tell who she was... But she was short."

"Okay. So she was right after Asajima went into the wing, correct?"

"Yes. It must have been around 3:08, just before sensei returned."

"…"

The two detectives from the prefectural police exchanged glances.

If that's true, then besides the victim, there was someone else in that backstage. Her words will become extremely important testimony…

"You don't believe me, do you?"

Nao, observing their expressions, spoke pointedly.

"The detective standing behind you didn't believe me either."

"Ah, no, no, it's not that I don't believe you."

Shirato explained awkwardly.

"Because no one else saw that girl…"

"Which is why I'm telling you, my classmate Nakamiya was standing by the window of the ladies' restroom!"

Nao raised her voice, almost in protest.

"You could ask Nakamiya. She should remember that girl passing through the corridor."

"But she testified she didn't know…"

"Stop! I understand."

Continued arguing wouldn't advance things. Sendou interrupted them:

"Sugawa-san, let's tentatively take your testimony as truth."

"Really?"

"Yes. But, in the end, we're just provisionally believing. So, please continue with what happened next."

"…Alright."

Although it seemed she wasn't satisfied with such an ambiguous statement, Nao didn't dwell on the mysterious girl and continued discussing what happened in the old gym.

Her account was identical to Masumura's testimony. Sensei returned at 3:10. The two team members arrived shortly after, along with the badminton team members. She also wasn't clear on what caused the drum-like sound around 3:15. Drama club came in, and the body was discovered.

"I was shocked. Or rather, I still am shocked. Asajima was such a nice person; how could something like this happen…"

"I understand your feelings, and we'll definitely catch the criminal!"

Sendou encouraged her consistently as she bowed her head again.

"Next, I'd like to ask you something very important… While you were in the gym, besides the drama club members, did you see anyone else come out from backstage?"

"No, I didn't see anyone come out."

"Are you certain?"

"I'm certain. There were hardly any people in the gym. If someone moved about, I would notice immediately. The same for the upstairs corridor; if someone passed by, I could discern it through sound and tell-tale signs."

Hearing this from someone who trained in the gym daily, it seemed credible.

"I see. Thank you!"

When she heard Sendou express gratitude, Nao Sugawa said "You're welcome," and stood up from her metal chair.

Just as she turned to leave for the corridor, she glanced at Hakata once more.

Their eyes met.

"…What is it?"

"Uh, nothing."

She bashfully turned her face away and exited the gym. Instead, it was Hakata who felt unsettled.

"…Sendou Police Inspector, did I do something to her?"

"I don't know. Maybe she has a crush on you?"

The inspector joked before continuing:

"However, was there another person backstage?… Shirato, you said no one else saw that mysterious girl, is that true?"

"Yeah, as Sugawa said, a student named Nakamiya was waiting for her friend where she could see the corridor. Nakamiya testified she doesn't remember."

"Oh…"

Sendou crossed his arms over his chest, and Hakata fell into contemplation beside him. It seemed time to get those brain gears going.

Assuming Nao Sugawa's testimony is true, then the girl who went backstage is highly likely the murderer of Asajima. The probability of this is significant. After all, she went in and didn't come out. Perhaps to avoid being seen, hypothesizing she escaped from a wing's door, seems plausible.

However, other students claim not to have seen her.

If so, it's possible Nao Sugawa is lying—but why lie?

"Then, let's next call in Nakamiya."

While standing in confrontation with his notebook, Hakata's musings were interrupted by Sendou pulling out a list of the relevant people from his chest pocket. He unfolded the list, examined it:

"Yes, however, it's better to inquire according to the sequence of those who entered the gym. If so, it would be one of the table tennis team members… huh?"

Seeming to notice something, Sendou brought the list closer to his nose.

"Hey, Hakata, take a look at this!"

"Eh? What is it?"

Per instructions, Hakata glanced at the list he'd yet to look at—he shivered all over.

"That captain was eyeing you the whole time, surely this is why."

"…"

He couldn't answer.

"Shirato, bring in those two table tennis team members next," Sendou instructed, unfazed by his subordinate's state.

The investigative officer rushed towards the empty classroom and swiftly brought the two girls.

During this, Hakata was dumbfounded, let alone engaging his brain. Instead, he felt almost faint from dizziness. When the two girls in practice uniforms appeared at the gym's entrance, he nearly collapsed from despair.

"Please have a seat… Oh, there aren't enough chairs. Hey, lend your chair to them!"

Unaware chief instructed. Following orders, Hakata stood up with shaky steps.

"Oh, right, I'm Sendou from the Prefectural Police. This is my subordinate Hakata."

"Hakata…?"

The lively girl with a ponytail twirled her eyes, reacting to his surname.

"Hey, what a coincidence, she's also named Hakata… Huh?"

The ponytail girl looked at her companion and showed signs of apprehension.

Understandable. The other girl was unusually stiff, eyes wide open, frozen in place.

At the end of her line of sight was Hakata, equally stupefied.

"What are you doing here?"

He greeted the embodiment of his harsh reality and melancholy.

"I should be asking you, brother, why are you here?"

Yuzuno Hakata replied.

5 The Giant Locked Room

"And that's how it is, this is my sister, Yuzuno."

"And that's how it is, this guy is my brother."

"What!?"—A chorus resounded from the gym's ceiling, making Hakata want to cover his ears.

"Sister? Hakata, this is your sister?"

"Hey, it's your sister, huh. I was wondering about the same surname."

"Brother? This guy? No way, what a coincidence. Oh, Yuzuno, your brother is a detective? Weren't you saying he was a civil servant?"

"Police officers are civil servants too."

"True, but…!"

"…However, I never expected my brother to end up here."

"I also didn't expect you'd be involved in this case."

This was a lie. To be accurate, it was more like "I also hoped you wouldn't get entangled in this case."

"I-I'm not entangled in any case!"

His sister, ten years younger, emphasized, seeming quite unconvinced.

"I just happened to be around when Asajima was discovered."

"That counts as being involved!"

Although he was unwilling, he had to question his dear sister as an important witness.

"I heard you had a sister in high school, but I didn't think she'd be here… Is this why you sighed earlier?"

"Let's leave it here, please start questioning soon..."

Interrupting the competent inspector's unnecessary reasoning, Hakata dismissed further inquiries. About this, he preferred that someone else not pry further. 

Sendou turned back to the two girls, issuing apologies repeatedly, then said:

"So let's get back on track. I'd like both of you to answer some questions. First, your names and class."

"I'm Sanae Nonami from class 2-year 1."

"…I'm Yuzuno Hakata, also from class 2-year 1."

Hearing his family introduce herself so politely felt strange.
"Um, you both are on the girls' table tennis team, right? What time did you arrive here today?"

"At three ten. I even checked the clock, so there's no mistake." replied Sanae Nonami, the girl with the ponytail.

"Before that, where were you? What were you doing?"

"Doing what... Well, after class, we went straight to the team activity room to change clothes, then came here. It was our turn to do the preparation work today, so we were in a hurry."

"During that time, it was just the two of you?"

"Yes, so we have an alibi! We even ran into other team members on our way to the gym."

This was a kid who wasn't shy even in front of professionals. Hakata couldn't help but think that this child had the demeanor of a detective's sister.

"No, we're just asking for reference... Then, when you entered the gym, was there anyone there?"

"Captain Sugawa and Advisor Masumura were there. They were stretching over there."

Sanae pointed to the same spot Nao Sugawa mentioned earlier.

"Was there anything unusual in the gym at the time?"

"Well, nothing unusual... However, the curtain was down, which I found a bit strange."

"I found it strange too."

Yuzuno nodded in agreement.

The subsequent testimonies were consistent with those provided by others: the badminton team's thumping sounds, the drama club's entry, and the discovery of the body.

"It scared me! It's shocking enough that someone died, and it was Asajima!"

"Did you know Asajima before?"

"Yes, he was the head of the broadcasting station, quite well known. I've seen him using the broadcasting room here a few times. Although I wasn't very familiar with him, we kind of knew each other."

"He was a nice person... How could something like this happen?"

Yuzuno muttered gloomily. Hakata felt uncomfortable.

"Well... what happened then? I heard Advisor Masumura asked you to gather in one place."

"That's right. He told us, Sugawa, and the drama club not to move, and asked two people from the badminton team to run to the office to call for help. Then, after hearing Yuzuno's scream, the student council president Masaki, and a senpai I don't know, also came into the gym to see what happened. They were gathered too. It seemed they wanted to preserve the scene."

You screamed! Hakata glanced at his sister. She glared back at him as if to say, "You're annoying, it's not like I had a choice." Then Hakata said:

"That senpai was initially standing in front of the restroom window. I saw her when I entered the gym. At the time, I thought it was strange why she would stand there on a rainy day."

"Oh... So that was Nakamura."

"Yes, that's what the captain called her."

"Understood. Thank you very much!... Now for the final question."

Sendou leaned in closer to ask the most crucial question.

"When you were in the gym, besides the drama club members, did anyone else come out from backstage?"

"...I don't think so."

"I don't think so either."

Both of them shook their heads earnestly. Thus, Hakata's time in what felt like purgatory ended unexpectedly smoothly.

"You're not very considerate."

After Yuzuno and the others left the gym, Sendou joked with him:

"Since it's the school your sister attends, why didn't you mention it earlier?"

"I thought it was irrelevant."

"Do you think I'd let you dodge because of that?"

"No, um..."

There was that reason, but the main reason was his own attempt to avoid reality. But he didn't want to say that out loud.

"Don't worry, I won't let you dodge. Even if I wanted to find a replacement for you, we're short-handed in the investigation team now. And your sister isn't a suspect, isn't that good? She couldn't have been involved in a crime."

"That's not something to joke about."

"Haha, sorry, sorry. Anyway, don't mix personal and official matters!"

"...I understand."

Though he understood.

The mental burden was immeasurable.

"The next two are here."

In his usual calm manner, Shirato notified Hakata and Sendou. The fourth group of witnesses was two male badminton team members, first-year students Hamaoka and Nagase.

They claimed to have arrived at the gym around three ten or twelve. Although no new valuable information was obtained, when asked about the girl Nakamura standing outside the gym, their testimony was intriguing.

"Oh, she was indeed there. She was standing in front of the restroom window, playing with her phone under an umbrella. Then, we saw members of the drama club coming over from the other side."

"The drama club. How many people?"

"Hmm... four, I think."

"They all had umbrellas and were pulling a two-wheeled cart covered with a blue plastic sheet."

"They might have been moving props for the drama."

Hamaoka and Nagase chatted alternately about the situation. Sendou thanked them and let them go.

"...Well, it's finally the drama club students' turn."

The drama club.

If you don't consider Nao Sugawa's testimony, they're the only ones familiar with the backstage situation. According to Shirato, the backstage was a "sealed room," a point that needed to be verified with them.

Hakata's right hand, which held the pen, was already sweaty.

"I'm Kazuya Kajiwara from second-year class 1, head of the drama club."

"I'm Aimi Sanjo from second-year class 3, vice head of the club."

"Oh, I'm Keisuke Shiga from first-year class 5."

"I'm Tsubaki Matsue from first-year class 6."

The drama club members introduced themselves one by one. Although Sendou had also set out chairs, there weren't enough, so the club head Kajiwara had to stand alone. No matter how you looked at it, this scene of four students sitting across from a group of people in suits resembled a drama performance, making Hakata feel a bit odd.

Sendou asked about what they did after school until just now, and Kajiwara spoke on behalf of everyone:

"Like usual, we gathered in the drama club activity room first. Right after class, around three oh three, Matsue and I entered the activity room. Shiga followed shortly. At that time, it was probably three oh five. The last to arrive was Sanjo at around three ten. Normally, we would linger in the activity room even after everyone arrived, but since it was raining today and the preparation work takes time, we thought it's better to be quick, so we headed here immediately."

"You came to the gym to rehearse, right?"

"Yes. Our performance is coming up soon. It's a comedy called 'It Will Fall from the Sky Again Today,' about..."

"Ah, you don't need to elaborate on that. Just continue."

"Oh... So we used a two-wheeled cart to transport large props to the gym. What time did we arrive?"

"Three fifteen."

The competent girl named Tsubaki Matsue rescued the situation.

"When the club head took out the key to open the door, I checked my watch, so I'm certain. I remember thinking we arrived five minutes earlier than usual."

"Yes, yes, that's right, it was three fifteen. As expected, Matsue is reliable."

"The door you opened was the one on the left side of the stage, near the restroom?"

"Yes. That door is exclusively used by us. It's like the drama club's dedicated entry and exit."

"You have a key for that door? Matsue just said it was you who opened it."

"Yes. Because of frequent use, we requested the teachers to provide us with a key."

"Are you the only one with that key?"

"I'm the only one, and I've never lent it to other members. Besides, no other key has been made, and the original key is well kept in the office. By the way, we don't have a key for the right side stage door. The only key is kept in the office."

Without being asked, he supplied information continuously. Early on, Sanae Nonami also did the same. Have today's kids been watching too many police dramas?

"Three fifteen. Around this time, other people began hearing drumbeat sounds. What about you guys?"

"Huh? Drumming? I don't remember hearing it. How about everyone else?"

Kajiwara asked the other members, and they all tilted their heads, implying they didn't know.

"Well, the sound of the rain was too loud, so we couldn't tell. Sorry... Oh, but I remember there was someone standing by the door. I think it was Nakamura from class 4."

Another sighting of Nakamura came up. It seemed she never left that spot.

"What happened after you entered the gym?"

"Well, we were about to push the two-wheeled cart in when Sanjo greeted the athletic club members..."

"Wait, wait! What do you mean by pushing the cart in?"

"Since it's raining, if we remove the plastic sheet outside, the props would get wet, so we always push the entire cart inside. But if we just push it in the usual way, it gets stuck on the steps, so..."

"What?... what?"

"Ah?"

Both sides' dialogue was off beat; Sendou and Kajiwara exchanged question marks. Shirato then mumbled:

"Maybe it'll be easier to understand if they demonstrate it."

Because it was said by the detective, it was unclear if it was a joke or serious. But the tragedy was that the drama club members at least took it seriously. Aimi Sanjo clapped her hands and said, "Yes!" and Kajiwara snapped his fingers in agreement, saying, "That might be a good idea!"

This was completely unexpected for Hakata and the others.

"A demonstration, you mean..."

"Reenacting what happened at three fifteen on the side stage. Isn't it easier to understand this way?"

"No, no need to..."

Before they could stop them, the drama club members enthusiastically headed to the side stage. Sendou and Hakata exchanged glances and had no choice but to follow them.

Ah, these speechless high school students...

"The cart we dragged over is that one."

Kajiwara pointed outside through the glass. About three meters in front of the utility storage, stood a two-wheeled cart commonly seen in rural areas. The wind had blown the plastic sheet halfway open, revealing a pile of props, wardrobes, tables, cardboard boxes, antique-style chairs, and more for the drama.

"The four of us transported this thing. There are too many steps inside the school, so we always go around from outside. But since it's raining today, holding an umbrella was quite a task."

"I see... then?"

Sendou was getting impatient. Although asking questions inside the gymnasium was supposed to help understanding, he was reluctant to enter the scene regardless.

"First, unlock the door and open it wide to push the cart in."

"Can the cart really fit through this door?"

Hakata compared the sizes of the door and the cart. Although it was a double-opening door, it was at most one meter twenty wide, and it seemed the width wasn't enough.

"Just barely fits. When using the old gymnasium on rainy days, we always do it this way. Take a look."

With an air of confidence, the club president walked in front while the other club members put on their shoes, opened the double doors, and headed towards the cart. Kajiwara and Aimi Sanjo, both second-year students, grabbed the handles, while first-year students Shiga and Matsue pushed from the other end. They started moving towards the entrance from Kajiwara's side.

"See!"

The door frame and plastic sheet rubbed against each other, allowing the front half of the cart to barely pass through the doorway. However, only the front half passed, as the cart stopped midway.

As Kajiwara described in his testimony, a ten-centimeter step obstructed the wheels in front of a small concrete area.

"Then, Shiga, Matsue, and I tried to push the cart over the step, while Sanjo went ahead to the stage."

"Ahead? Why?"

"Well, we have an unspoken rule to notify the sports club when using the gym. Our lines sound exotic to the sports club and might distract them, so it's a necessary courtesy."

"Right, right."

"So today, Sanjo used the excuse of notifying them to sneak away from pulling the cart."

Thus, the drama club members began reenacting the scene. Kajiwara mimed dragging the cart with all his might. Aimi Sanjo dashed past Hakata and the others, opened the wooden door.

"Hey, Sanjo, don't run!"

"Ah, Sanjo-senpai is sneaky! Give us a hand!"

First-year students Keisuke Shiga's melodious voice overlapped with Kajiwara's lines. Aimi acted coolly, answering, "I'll go ahead!"

"At that moment, I glanced at the stage and saw the curtain was down."

She turned back, speaking in a normal tone for the testimony. Then added, "Eek? The curtain is down."

"What are you saying? Why is the curtain down?"

Responding, Kajiwara walked towards Aimi Sanjo from the cart. The loads of goods and plastic sheets blocked the two on the other side of the cart. Only their complaints could be heard: "No way! Even the president left!" "Who's going to pull the cart now?"

This felt like a comedy sketch. However, it indeed conveyed the situation clearly.

"Then, I stepped forward to ask the sports team members who had lowered the curtain."

"That part we know. The captain of the table tennis team said it was Asajima who lowered it."

"Yes, yes. Then I thought, why did the broadcasting station head lower the curtain? But I didn't take it seriously and asked Sanjo to raise the curtain."

"I switched on the curtain elevator."

The electric lift was installed on the left side stage, right next to the door leading outside. She demonstrated the action of pressing the switch. Kajiwara took advantage of this moment to go up the stage.

"The curtain slowly rose, and I went up to the stage like this... From the side stage view, the podium was blocked, so I didn't notice Asajima was stabbed to death."

"Hmm... what happened next?"

Sendou, too, seemed interested in the reenactment of the moment the body was discovered and urged him to continue.

"Then the girls from the table tennis team screamed, and I panicked, shouting 'Oh no! Asajima is dead!' Sanjo stood beside me, dumbfounded."

"What about you two?"

Sendou turned back to the door and asked. The two first-year students moved the cart back from the doorway, returned, and said:

"We were at a loss when the president left. If we only pushed from behind, the tires couldn't get over the step. One of us wanted to go to the front, but the cart blocked the door, leaving no room to maneuver."

"At that moment, we heard the scream and the president's shout, and we were startled. We decided to go in and have a look, so we pulled the cart out just like before and went into the gym."

"What about the door lock?"

The inspector pressed on. "I locked the door," replied the freckled-faced student Shiga.

"But at the time, I didn't think much of it. We always lock the door unconsciously out of habit."

"Oh... you lock the door so well."

"Huh? Really? Wow, getting praised by a detective makes me happy!"

"The first-year students in our troupe are really capable."

Shiga blushed and smiled sheepishly while Kajiwara nodded in agreement. The drama club members looked happy, but the detectives were not as cheerful.

"Shiga, I have another question for you. While the door was open, did anyone pass by you and go outside?"

"Uh, no."

"Are you sure? Could someone have passed by without you noticing?"

"I don't think so."

Tsubaki Matsue coldly replied. "The door was always blocked by the cart while it was open. Physically, it's impossible for anyone to pass through. We can't even go around from the front right now."

"...Indeed."

It's true; passing through a doorway blocked by the cart as it was just now would be impossible for anyone. The gap between the cart's wheels was about thirty centimeters, making it impossible for anyone unnoticed to slip through.

"Then Kajiwara, when you opened the door, it was indeed locked?"

"Yes, it was definitely locked. I felt it while unlocking it."

"I see... and then you were all gathered by Advisor Masumura and did not move, correct?"

"Yes."
"I didn't touch the body at all, nor did I touch the stage.”

"And this is very important. Besides you guys, the backstage..."

"No one was there. From what we saw."

"Oh...well, thank you then."

Thank you too!—Just like the curtain call at the end of a performance, they nodded in gratitude.

"You've worked hard. I am Tsuchiya from the second police station at Kaze Hill.”

Called in by Sendou following the drama club, a young patrol officer near Yusaku Hakata's age saluted crisply. His eyes were filled with a passion and sincerity that seemed to burn through people.

"Officer Tsuchiya, I heard you were the first to arrive and secure the scene."

"Yes. I confirmed the body and conducted a simple search of the scene."

"Oh...well, let me ask you, what were the conditions of the entrances and exits backstage then?"

"Yes. After confirming the body, I immediately checked the entrance and exit on the left stage and right stage, both doors were locked."

"And the windows? Did you check the restroom?"

"Yes. I checked all the windows, including those on the second floor and in the restroom; they were all closed and locked. I think it might be because of the rain."

"......"

Doors and windows were locked.

"Understood. You may go."

"Yes. I'm taking my leave!"

With another standard salute, the patrol officer returned to his previous post—to face the onlookers gathering one after another. Hakata and Sendou watched his figure blankly, while Shirato coughed awkwardly.

"Let's sort through the information."

After a moment of silence, Yusaku Hakata opened his notebook.

"No one walked out to the front of the stage from inside the curtains or the wings. When the drama club arrived, the left stage door was indeed locked. Also, while the door was open, it was physically impossible for anyone to get outside. When the door was closed again, it was locked from inside."

With each confirmed fact, the wrinkles between Sendou’s brows deepened.

"There are two keys for that left stage door, held by the drama club head and the office administration. However, from when Tomoki Asajima appeared at the gym at 3:03 p.m., he was always with other club members, he has an alibi. Officer Shirato, is there any record of the key being taken from the office?"

"If there were, I would have reported it already," the local police answered.

"Additionally, there’s no record of the right stage door key being taken out in recent months. Since there are many other exits, there’s no necessity to go through there."

"That's true...so the right stage door couldn't have been used. Yet when Tsuchiya checked, the windows and doors were locked. And Tomoki Asajima was murdered on stage..."

"Could someone be hiding somewhere? You see, in places like gymnasiums, there's usually space under the stage for folding chairs."

"This is an old building, it doesn’t have such facilities. There's no passage above or behind the stage."

"How about the broadcasting room then?" Sendou asked unwillingly. However, Shirato shook his head, shattering the last hope.

"Didn't I already say? We've thoroughly checked the broadcasting station; there's no place for someone to hide."

"Then..."

"That's how it is."

Hakata closed his notebook and sighed. It was his second sigh that day.

"Officer Shirato's investigation is still accurate. This enormous backstage was completely a sealed room when the murder occurred!"

6 The Last Remaining Signpost—Sealed Room Murder.

"How can this be!"—If one could laugh off such a thing, how easy it would be.

An impossible situation occurred. In an inescapable space, the murderer killed the boy and then vanished.

"What is going on here?"

Hakata, helpless, glanced at his superior’s expression. Sendou stood still, lost in thought.

Despite encountering such a bizarre situation, his eyes did not lose their luster. Instead, they shone even more brightly, as if he had grasped a clue.

"...If the backstage is a sealed room..." he murmured in a voice only Hakata could hear.

"There's only one possible explanation."

"Huh?"

Only one—

Does that mean there's already a lead?

"Officer Sendou, have you found something?"

"Perhaps." When he used the word "perhaps," he was usually quite confident.

"Re-really? But the scene is a sealed room..."

"Precisely because it's a sealed room! This isn’t like you, Hakata. Calm down and read the records again."

There was deeper meaning in his words. Then Sendou instructed Shirato:

"Shirato, let’s continue our inquiries. Please bring in the two students who entered the gym after hearing the scream."

The final witnesses to arrive were a contrasting duo.

One was a boy, wearing metal-framed glasses, with his school tie neatly in place, looking the very image of a model student. However, he wasn’t the kind who just buried himself in books; his naturally curly hair gave him a fashionable look that seemed popular with girls. Although not particularly tall, his upright posture showed he had plenty of confidence.

The other was a girl with golden wavy hair and sharp eyes that rivaled even Sendou’s. Her cardigan's collar was unbuttoned, the red ribbon loosely hung, making her seem unapproachable. Though dressed like a trendy girl, her lack of makeup made her more like a juvenile delinquent leader—such were the outdated thoughts running through Hakata’s mind.

"I am Akihiro Masaki from class 2-4, the student council president of this school."

"I’m Ryoko Nakamura from class 2-4. Huh? Do I have to say my name too, Rieko."

Their ways of speaking were completely opposite. Yet, there was some similarity.

"You both are from the same class."

“Yes.”

“We’re not really friends.”

Rieko Nakamura said bluntly. Masaki gave a wry smile, shrugged, and his smile was mature, like an adult facing a child’s prank.

“I heard you two came into the gym out of curiosity after hearing a scream. Can you tell us where you were and what you were doing at the time?”

"I was writing documents for a meeting in the student council's supplies office."

Without waiting for any order of speaking, Masaki promptly started explaining.

"I could have written in the student council office, but I needed the financial records stored in the supplies office as a reference. The supplies office is right next to the hallway, so you can clearly see the gymnasium through the window. At around 3:15 p.m... no, around 3:16 p.m., I heard a girl scream mixed with the sound of rain. Curious about what happened, I ran to the gym to check."

“Hmm... when did you get to the supplies office?”

“Around 2:55 p.m. I spent some time compiling the records and was there the whole time.”

Wasn't 2:55 during class time? Hakata was about to ask, but then realized:

Class 2-4, isn't that the same class as Nao Sugawa from the table tennis team? Class 4 finishes early, so students from this class can leave the classroom earlier than others. That’s all.

—Wait! Nao Sugawa?

Hakata’s head felt like it had been struck by lightning. He suddenly realized the implications of what Sendou had said earlier.

Nao Sugawa. A sealed room.

—Only one possibility.

"Was anyone else in the supplies office with you?"

No one paid attention to his moment of realization, and the questioning continued. In response to Sendou's question, Masaki answered honestly: "No one."

"Does this mean you don’t have an alibi?"

"No, no, we’re not suspecting you."

"Let me tell you first that I made a call to a council member, Vice President Chizuru Yatsuhashi, around 3:10. I informed her that I was in the supplies office writing documents and would bring them to the student council office when done."

"Alright, got it... Now let’s have Nakamura tell her story."

"Well... I went to wait for my friend outside the gym as soon as class ended at 2:50. Then I heard a scream, looked inside, and that's it."

Rieko replied gloomily.

"What time did you specifically start waiting there?"

"Huh? I can’t answer that... but I think it was around three, almost."

"I took a look outside when I first went into the supplies office, she wasn’t there then. When I looked again around three, she was already standing there."

Masaki interjected. As expected, he didn’t shy away from attention as the student council president.

“If that's the case, let’s say it was 2:57 then. Nakamura, at three o’clock, did you see your classmate Sugawa and Mr. Masumura walking into the gym?”

“Uh-huh—I do remember seeing that.”

“Then, did you see Asajima entering the gym about three minutes after Sugawa and Masumura?”

“I saw him too. It was about three minutes after Sugawa and the others went in.”

“That student was indeed Asajima?”

“...Yes, it was definitely him.”

At that very moment, Rieko Nakamura frowned, and her already intimidating gaze became even sharper. Hakata sensed a discordance. On one hand, her frowning expression was concerning; on the other, this girl, seemingly unrelated to the broadcasting station, was so familiar with Asajima from a different year that she could definitively say “it was definitely him.” That seemed puzzling.

“But then I was playing with my phone and don’t really remember what happened.”

“Did you see Mr. Masumura leaving the gym or the first-year members of the girls' table tennis team entering?”

“Hmm, well... I don't remember that.”

“A female student in a school uniform entered the gym around 3:08, did you see that?”

Nakamura thought for a moment with a conflicted “um—” then shook her head, swinging her golden hair.

“I don’t know about that either.”

“...I see.”

A sharp glance flashed in Sendou’s eyes.

“Then around 3:15, the drama club arrived at the gym. Is that right?”

“Oh yes. They came in through the door near me, pushing a two-wheeled cart. Then I immediately heard a scream.”

“Okay, got it. Did you hear any drum-like sounds when the drama club arrived?”

“Well, I don’t know about that.”

“What did you do after hearing the scream?”

“Like I said, I went into the gym. I wanted to use the door the drama club used, but they locked it, so I had no choice but to enter through the hallway door. That’s when a teacher called me.”

“From the time you heard the scream until the drama club members locked the door, did anyone come out of the right stage door?”

“No one.”

She seemed confident in this memory. After pondering silently for a moment, Sendou shifted focus:

"Did you and Masaki both look inside through the hallway window at the same time?"

"No, Nakamura was closer. When I went in to check the situation, she was being gathered in front of the stage." 

The student council president answered immediately.

“So, the last person to enter the gym was Masaki... for the sake of being thorough, did you see anyone come out of the gym?”

“No, not a single person.”

Another immediate answer.

“Okay...well, thank you! Both of you can leave now.”

After the last question, Masaki stood, saluted, and said, “Goodbye.” Rieko Nakamura stood up, groaning and rubbing her shoulders. The contrast between the two was sharp once more.

Hakata suddenly remembered that his sister had mentioned finding it strange to see her standing in the rain.

“Nakamura, why were you waiting for your friend there? Meetings are usually at entrances, right?”

He called after the departing Nakamura. The golden-haired girl turned back with a simple answer:

“...I can choose where I want to meet, can’t I?”

Such a classic adolescent response.

A few minutes later, Sendou and Hakata were having a cigarette in the hallway. Smoking was prohibited in all school buildings, including the gymnasium, so they came outside. However, after being confined in the closed space where the murder took place, the outdoor air and the openness of the clouded sky felt refreshing.

But, of course, their topic of conversation was the case. Standing beside Sendou, who was blowing smoke rings, Hakata re-read the summarized witness statements in his notebook.

3:00 Shintaro Masumura and Nao Sugawa arrive at the gym.

3:03 Tomoki Asajima enters the gym and goes backstage, lowering the curtain.

3:05 Masumura returns to his office.

3:08 (A mysterious girl enters the gym, heading backstage?)

3:10 Masumura returns. Yuzuno Hakata and Sanae Nonami enter the gym.

3:12 Two badminton club students enter the gym.

3:15 Four drama club members enter the gym from the left stage door.

3:16 The body is discovered.

"As you’ve also confirmed, the scene was a sealed room."

Based on all the notes from his subordinate, Sendou began confirming facts one by one.

“However, the key point here is not that the stage was locked on the outside, but that it was under constant watch. In other words, if the eyes watching were fewer, then there would be a moment to enter or leave the sealed room. And indeed, such a moment existed.”

“You mean when Masumura returned to his office, leaving only Nao Sugawa in the gym…”

Indeed. From 3:05 to 3:10, only Tomoki Asajima and Nao Sugawa were in the gym. In other words, Nao Sugawa was the only person who had the chance to be alone with the victim.

“From a physical standpoint, the backstage was a locked room. Since the stage was under constant surveillance at other times, this was the only opportunity to kill Asajima. Nao Sugawa claimed to see another girl entering the backstage, but no one else witnessed this girl.”

“There’s clearer evidence about the mysterious girl. When the drama club entered the backstage, and when Officer Tsuchiya investigated the scene, there wasn’t a single person there, and the doors were locked. It’s unclear where the girl who entered the backstage went.”

Given that, the answer is simple and clear—there was no such girl from the start.

“So, the murderer is Nao Sugawa…”

“We can only think so.”

Sendou exhaled a heavy puff of smoke.

“Although her motive is still unclear, they were teenagers at a sensitive age. Perhaps something happened between the two.”

“That makes sense. She was carrying a racquet cover and a shoe bag when she entered the gym. Those two items are the perfect size for hiding a knife...”

“It wouldn’t be strange for Asajima to come to the gym after school to talk to the table tennis captain. Perhaps they had already arranged to meet.”

The more they thought about it, the more suspicious Nao Sugawa seemed.

“But why would she go out of her way to drag the body to a place where it would be hard to find?”

“That’s something only she could answer... Similarly, it’s a mystery why Asajima lowered the curtain. It’s possible that Sugawa instructed him to do so.”

“Then what about the bowtie on the side stage and the umbrella without fingerprints in the men's restroom?”

“Those things have nothing to do with the case, perhaps? Bowties and umbrellas could be found anywhere in the school.”

“Well...that’s true.”

In the moments that followed, Hakata searched for elements to deny the conclusion that Nao Sugawa was the culprit. But all efforts were in vain.

She was the only one who ever broke the sealed room. Once this was clear, the conclusion was evident.

“The murderer is Nao Sugawa.”

Hakata said it again.

Suiting short hair, she appeared to be a responsible-looking girl.
The captain of the girls' table tennis team. 

——If Yuzuno found out about this, how shocked would she be? 

"Wait!" 

Yes, she would definitely shout like that... 

Hakata snapped out of his thoughts and looked towards the school building, then fell silent. Standing at the entrance of the corridor was none other than his younger sister. 

"Hey! What are you doing standing here..." 

"Captain Sagawa can't possibly be the murderer! The captain can't possibly be the murderer!" 

Ignoring her brother's chaotic mind, Yuzuno strode towards him with determined steps. Her eyes burned with excitement. 

"On what grounds do you say the captain is the murderer? Take back what you said! Sagawa couldn't have killed anyone!" 

"Hold on, hold on, Hakata. Please calm down!" 

Sendou was also at a loss with this unexpected objector and hastily held her back. 

"Weren't you in the waiting classroom? Why are you still here?" 

"...I said I had to go to the bathroom and came out." 

"Didn't the detectives walk you to the bathroom?" 

"They did, but there was a commotion from onlookers, and they went to assist there. I wanted to see how the investigation was going, so I peeked and overheard you two talking in the corridor..." 

So she was eavesdropping on the detectives. This is really... Hakata was speechless. His sister always had this odd proactive nature in strange situations. 

"Listen, whether or not it concerns me doesn't matter. You said student Sagawa is the murderer. What's going on?" 

The emotional girl's repeated questioning left the two detectives at a loss. What’s really going on — how should they answer? 

"...Yuzuno, since you overheard our conversation, you should understand, right?" 

Hakata gently explained, as if coaxing a troublesome child. 

"The scene was a closed room. Only student Sagawa had the opportunity to bypass it." 

"But, but since it was a closed room, it could've been suicide!" 

"That's not possible. As you saw, Asajima was stabbed, and there are no fingerprints on the murder weapon. Moreover, the body was moved onto the stage after being killed." 

"So student Sagawa's testimony is true that there was someone backstage. Didn't she say she saw a girl going in?" 

"If you heard that, you should also know what we discussed next. The mysterious girl wasn’t in the gym. That means Sagawa was lying." 

"Sagawa wouldn't lie..." 

Tears ran down Yuzuno's cheeks. 

How many years had it been since Hakata last saw his sister cry? Thoroughly flustered, he wondered if his way of speaking was too harsh. 

——But, it's better this way. Because it's the truth. 

"Sagawa was at the gym with teacher Masumura. Isn’t it a coincidence that the teacher returned to the office? Sagawa actually didn't have the chance to kill..." 

"You're quite emotional, but your points are sharp." 

Sendou said after moving the cigarette from his mouth. 

"But speaking of that, it was also coincidental that Sagawa was at the gym with teacher Masumura. If the teacher had stayed in the gym, she might have abandoned her plans. But as it turned out, the teacher returned to the office, creating a gap for the crime to be carried out. So she killed..." 

"Student Sagawa wouldn't kill!" 

Yuzuno raised her voice as if trying to erase Sendou's words. Then she turned around, wiping her tears as she ran down the corridor. 

No doubt she wouldn't obediently return to the waiting room for those involved. 

"Ah... hey! Yuzuno!" 

"It’s alright, let her go." 

While Hakata wanted to chase after her, his superior calmly held his shoulder. 

"At their age, even though they don’t surrender easily, they know resisting is useless. She just wants some time alone." 

"S-sorry... my sister really is clueless." 

"I said it’s alright. Listen, the senior she trusted turned out to be the murderer, of course she’d be emotional." 

Indeed, perhaps it was himself growing numb from doing such troublesome work. 

"However, I'm really surprised they let someone under surveillance slip through their fingers, the guys at Hodono Valley Police Station need a good scolding." 

Sendou half-jokingly put out his cigarette in a portable ashtray and walked back to the gym. His broad-shouldered back conveyed a sense of relief after solving the case. 

Hakata hesitated for a moment. He was torn over whether to comfort his sister, possibly crying her heart out, but he immediately thought of his primary duty, so he followed after his superior’s back. 

Inconsiderate. 

Her brother was surely saying this about her. 

No, she understood. Their reasoning was beyond reasonable, irrefutable. But Yuzuno still couldn’t possibly believe Captain Sagawa was a murderer. She absolutely couldn’t believe that her strong, beautiful, straightforward, training-enthused perfect senior would kill anyone. 

Tears flowed, ears ringing, Yuzuno let the whirlwind of emotions take her away. Her chest felt tight, as if she had lost a match — the stubborn refusal far outweighed her sadness. 

"Ah, ah..." 

She saw the end of the corridor just ahead, soon stopping. 

It’s long past six o'clock. The sunlight slanted over the deserted shoe racks. At some unknown point, she had crossed several school buildings and reached the entrance. 

"...What should I do?" 

She asked herself but found no answer. 

If this continues, that officer named Sendou will arrest Captain Sagawa. The circumstantial evidence was complete. No matter how much the captain, herself, or the teammates denied it, the police wouldn’t change their minds. 

I have to figure out a way to do something. I have to figure out a way to do something. 

But. 

"Think of a way... what way is there?" 

"Haven’t I told you to stay in the room?" 

Just as she mumbled those words in despair, a voice came from the depths of the corridor. 

"But, Vice President..." 

"I was the only one called over, if everyone were to go it’d just complicate things. Masaki can handle it, you should go back to the student council office." 

Two figures appeared, arguing as they walked down the corridor. A woman with classic Japanese beauty and a young girl with an adorable bob cut. 

"Hakata?" 

Just as the two were about to turn towards the second building, the bob-haired young girl noticed her and turned back to approach her. Yuzuno wiped away her tears and finally recognized who it was. Her classmate from first year class 2, student council officer Yukiko Hibiya. 

"Hakata, what are you doing here?" 

"Oh, nothing, nothing..." 

Yuzuno turned her face away, not wanting them to see her puffy eyes. However, the other young girl, the Yamato Nadeshiko, walked around to see her. 

She was a girl more suited to wearing kimono than any other attire. With shiny hair, skin fairer than Akita beauties, and slender legs peeking from her skirt hem. Most memorable were her moist eyes and smile at the corner of her lips. 

Hakata knew her name. 

"...Yatsuhashi, student?" 

That was the student council vice president, Chizuru Yatsuhashi. In last month's election, the second-year student ran alongside Masaki as a candidate and ultimately secured the position just below the president. According to Sanae, she was the third-ranked achiever among the second years. 

"...Oh?" 

The vice president shifted her moist pupils from Yuzuno back to her companion: 

"Hey, Hibiya, I told you to go back." 

"But, but, I still want to go with you..." 

"No. Stay put with Shiina." 

Under her gentle yet unyielding command, Yukiko reluctantly returned down the corridor. 

Then Chizuru turned to Yuzuno and said: 

"Why is the girl in the girls' table tennis team uniform crying here?" 

"Ah..." 

She could indeed tell she had been crying. 

"Well, it’s fine if you don’t say. Anyway, do you know what happened in the gym?" 

Although this was their first conversation, Chizuru spoke as if she were chatting with a friend. 

"The broadcast said there was an incident in the old gym, with rumors of a murder. Is that true? Was someone killed?" 

"Oh, yes... It was Asajima from the broadcasting station." 

"Asajima?" 

Chizuru's voice escalated two octaves. 

"Asajima was killed?… Tell me, is Masaki involved?" 

"Masaki? Yeah. He’s kind of a witness, you could say." 

"Not a suspect?" 

"I don’t think... he’s a suspect." 

Thinking of the real suspect, Captain Sagawa, Yuzuno involuntarily lowered her head again. 

"I see. That’s a relief." 

The vice president sighed in relief. 

"Actually, I got an internal call asking me to verify ‘the situation when Masaki called’, so I was quite anxious." 

"Oh... Then Yatsuhashi, you're now..." 

"Yes. I’m about to see the police... What are you doing here? Regular students should be out of the school and relevant individuals shouldn’t be wandering around alone." 

"..." 

She hesitated, unsure whether to explain. Saying it out loud wouldn’t make any difference, Chizuru might even scold her like her brother did. She silently let her gaze roam the floor. 

However, the right hand clutching the edge of her training uniform was suddenly held by Chizuru’s hands. 

When Yuzuno looked up, Chizuru was leaning in, gently smiling at her. Her eyes were close, the warmth transferring to her skin. Her lips seemed to silently say, "It’s alright." 

When she came back to her senses, Yuzuno found herself already recounting what had happened in the corridor. 

Whether it was the senior’s aura from Chizuru, who she serendipitously encountered, or because she simply wanted to pour out her thoughts to someone, or a combination of both, Yuzuno couldn’t figure out. In any case, Yuzuno held the hands comforting her and began explaining how Captain Sagawa had come under suspicion. Once she started, she couldn’t stop, revealing everything from the beginning. 

"I see." 

Chizuru seemed genuinely touched by her thoughts. 

"I’m also familiar with student Sagawa... She really wouldn’t do something like murder." 

"Right, right!" 

"But the evidence is clear." 

"Yes, yes..." 

"If she’s not the killer, we need to prove it to the police... I can’t think of any way." 

"..." 

She couldn’t agree. If even the trustworthy-looking vice president said there was no way, then it was indeed hopeless. 

Her tears threatened to flow again — Sagawa's voice resounded with a sobbing tone. No, she thought, she was just a high school student; how could she possibly dispel the police’s suspicion? 

"I do know someone who might be able to help." 

"Huh?" 

Hearing Chizuru's unexpected words, Yuzuno looked up. 

"You mean there’s someone who might be able to save Sagawa?" 

"Just one person. I don’t know if they can really help, but it's better than us worrying here. Because he’s different, he’s exceptionally smart." 

"He...?" 

Hearing this, Chizuru released her hand and pointed at the wall. They were at the entrance. On the large bulletin board was the midterm exam results. 

——She remembered. 

That was back when she was still living her normal life. From a time perspective, only three hours ago. When moving the table tennis tables, Sanae had casually mentioned: 

"The top of the second years..." 

"But, they might not want to help, right? He’s reportedly eccentric. Besides, hasn’t he probably gone home?" 

"No, maybe it won't be an issue." 

It wouldn’t be an issue even if he went home. This was because, as rumor had it, his home was within the school, residing in a room in the cultural activities club rooms. 

Yuzuno approached the bulletin board she would usually overlook. The person's name, alongside their unreal score, was written at the top of the list with "Second Year." 

Not "Umigame-kun." 

First Place: Tama Risome [Second Year (Class 1)]... 900 points 

This surname is pronounced “Urazome,” right? It really is rare. 

She looked back at Chizuru. The vice president who guided her nodded, her moist eyes fluttering. Then she encouraged her, “Good luck!” 

"Okay!" 

Yuzuno responded in the manner practiced during table tennis training. 

Rushing out the school building entrance, she ran directly towards the cultural activities club rooms. Unlike earlier, she now had a target direction. She sprinted forward, breaking through the damp air after the rain had ceased. 

For Yuzuno right now, this was the only possibility she could think of. 

To save Captain Sagawa, she could only rely on this person. 

This yet-unseen boy named Tama Risome. 

A traditional Japanese term for excellent women. 

Umigame is the Japanese pronunciation for "sea turtle."
Chapter Two: The Detective Appears

1. Meeting an Otaku

The destination, the culture club activity room, was quietly situated north of the second school building, in the center of three connected schoolhouses. Since activities were mainly indoors, this room was more luxurious compared to the sports clubs. If the sports team rooms looked like run-down apartments, the culture department's would resemble "Such-and-Such Heights," a high-end condo just five years old. The hallway's doors were lined up, filled with club items like guitar amplifiers and manga copiers.

The room Sanae mentioned was probably the westernmost on the first floor. Without searching, she walked quickly and found it immediately. There was a small window by the door, but with the curtains drawn, she couldn't see inside. A nameplate on the door, written with a fading brushstroke, identified it as the "Hyakunin Isshu Research Society."

She could easily guess the club activities but had never heard of such a society.

“…Okay!”

Yuzuno paused, then grabbed the door handle. Rumor had it that this room was always locked. She intended to check this first, then knock, but—

Click.

A small metallic sound came, and the door opened smoothly.

“Huh?”

Yuzuno was disappointed. If it wasn't always locked, it wouldn't be called "The Locked Room," right? Or was Sanae untrustworthy? Were the Hyakunin Isshu Society members diligently studying here day and night?

As she pondered, the door opened fully, leaving no room for hesitation. Yuzuno decided and quietly murmured “Excuse me…” before removing her shoes and entering.

She was greeted by about twenty young girls.

“…”

It was a room covered in anime posters, several larger than Yuzuno's torso. Guitar-hugging bands, trios in maid outfits on sofas, and pictures of black-haired high school girls making victory signs in naval uniforms–all adorned the walls. Other girls wore cat-eared headbands flying in the air or white cape skirts rowing boats, or had mascots on their shoulders while holding pink bows and arrows...

Colorful chaos indeed, but one thing was clear—this had nothing to do with Hyakunin Isshu.

In this poster-clad space, not even a hint of Hyakunin Isshu could be found. 

A short-legged table sat centrally, cluttered with half-drunk water bottles, magazines, manga, and DVDs. Piles of these items, alongside bookstore and anime shop bags, covered the floor. It wasn't disorganized as much as it was overstuffed; there was no room on the shelves. So “messy” was the only suitable description.

The right wall boasted a large iron bookshelf like those in special rooms. It held similar magazines, manga, and DVDs, occasionally interspersed with Blu-ray discs, CDs, and game software. All two-dimensional, with no space for three-dimensional objects. If exceptions were named, only specialty voice acting magazines could claim the spot, smiling anime girls around each corner.

Opposite stood a desk, a laptop, and a desktop computer functioning perfectly without their user present.

To the left, a bed nestled in the corner, the room's owner lying with his back to Yuzuno, school tie undone beside him. Occasionally, a page-flipping sound was audible. But he was definitely reading a bunkobon.

This guy was Tama Risome?

“Hello…”

Yuzuno found a place to step near the bed, ready to greet him—

“Why are you so late? What are you doing?”

But he spoke first.

“Huh? What am I doing?”

“How's the gymnasium? I heard something happened.”

More page flipping. Yuzuno was stunned. He had anticipated her needing advice and was waiting for her? Impressive! His hobbies might be odd, but maybe he was reliable.

“Uh, well, Sugawa is suspected by the police, so I thought to ask for your help…”

“Huh?”

It was then he turned to face her.

Black eyes met hers. He was a fine-featured young man. Although his lazy double eyelids let him down a bit. His skin was ghostly pale, his shirt’s top buttons were undone, displaying the curve of his collarbone.

He eyed Yuzuno and bluntly asked:

“Who are you?”

His tone was far from polite.

“Oh, I’m Yuzuno Hakata, a first-year.”

Yuzuno, though realizing the sudden shift in atmosphere, introduced herself still. He glanced aside and frowned slightly, saying:

“Yuzuno Hakata. Sounds like someone living in an apartment studying art.”

“Art...? No, I’m in the table tennis team.”

“You could tell. So, Hakata, let me ask you, how did you get in?”

“How did I get in…? Simply, through the door.”

She answered truthfully. Hearing this, he held his forehead as if suppressing a headache and said:

“That idiot... forgot to lock the door.”

“Huh?”

“Sorry, Hakata. I don't know why you're here, and I’d rather not know. As you see, this is a private space. Could you leave quickly? And forget everything here. So then, goodbye!”

He lay back on the bed, assuming an ushering-out posture.

Apparently, his earlier “Why so late?” was a mix-up, mistaking her for someone else. But now, she had no retreat.

“Are you… Tama Risome?”

“Risome? Never heard of him, you’re mistaken. Now, leave, quickly, and forget everything you saw!”

“Huh, you’re not Risome?”

What was going on? She wasn’t just unwelcome, she was a complete nuisance. Maybe she shouldn’t have entered uninvited.

Suddenly, the door was flung open. Entering the room was a girl with short hair, red-rimmed glasses, and a red hairclip. Yuzuno had a vague impression of her features but remembered the SLR camera around her neck. This memory linked to a club introduction event earlier after enrolling.

“Hmm, you’re the newspaper president... Sakasaka?”

“Ah! There’s someone here! Huh? Why?”

The girl's overreaction upon seeing Yuzuno was evident. Then she turned to the boy on the bed:

“Who is she, Tama? Your girlfriend?”

“Why she got in, blame you!”

“Huh?”

“I told you countless times to lock the door.”

“Oh, I’m sorry, I was in a rush earlier…”

“Apologies won’t help if a teacher or police come!”

Seriously!—he muttered while sitting up. His thin frame looked unhealthy.

“Oh, speaking of the police. Unbelievable news! The entire gymnasium’s shut off. I asked the police, and they wouldn’t say anything. In the end, when I wouldn’t leave, about five officers surrounded me, almost arresting me!”

Yuzuno understood. The detective probably left because of her disruption.

“That’s too bad; it’d be good if you were caught.”

“You’re so, so, so mean! I don’t want a criminal record at such a young age!”

“I get it, I get it. So, what happened?”

“Oh, uh, apparently it’s a murder. A student got killed.”

“Is that so?”

He turned to Yuzuno for confirmation. She nodded. The newspaper president, seeing this, asked:

“A table tennis team member? But wasn’t everyone using the gym sent home?”

“She found the body first.”

“Oh... huh? How do you know?”

Yuzuno was taken aback, inching closer to the boy.

“Huh? Huh? Huh?”

But the newspaper president seized her shoulders:

“You found the body? So you were on-scene? Really? Tell me everything. Who was killed? One of our students? When? Where? How? Did you see the killer? Who?”

“No, it’s not like that. Um…”

The girl shook Yuzuno's shoulders, eyes alight. Meanwhile, the drowsy boy gave a lazy yawn.

Already confused, and now only more so, Yuzuno had to shout:

“Wait up!”

2. Tama Risome

“Uh, there's something I want to ask.”

Once they were seated by the short table, Yuzuno spoke up. First, she pointed to the boy, unwilling to set aside his manga magazines despite having risen from the bed:

“This guy is Tama Risome, right? You called him Tama just now.”

“He’s Tama Risome.”

The bespectacled girl confirmed. The boy nodded, saying: “Seems like it.”

“You told me I had the wrong person earlier.”

“I don’t remember that. I was absorbed in this week’s magazine…”

An old-fashioned dodge.

“…Next, a second question. You’re the newspaper's Sakasaka, right?”

“Yes. I’m the newspaper president, Kaori Sakasaka from class 2-1. Nice to meet you.”

While introducing herself, Kaori handed over a business card. Yuzuno took it for the time being. Her name and title were printed imposingly in huge, bold letters.

“What’s your relationship with Risome?”

“We’re classmates.”

“That’s part of it, but we’ve known each other for ages, so I drop by here sometimes.”

If they were dating, she’d feel awkward about staying longer, but it seemed that wasn’t the case, which relieved Yuzuno... but why did she care?

“You visit… but isn’t this the Hyakunin Isshu club room?”

“That’s what we say officially. In reality, there are zero members; this is my domain.”

Risome answered plainly.

“Your domain? You mean you live here? In a place like this?”

“It’s quite cozy here. The activity building has water and toilets, and a public bath and laundromat are close by.”

Yuzuno thought any self-proclaimed room-dweller would run scared barefoot from this guy.

“Let me make some tea.”

Kaori said, deftly brewing some, while clearing a path through the magazine stacks.

A home appliance corner emerged, with a fridge, and microwave, even a rice cooker. He really treated this room as his.

“Why do you live here? What about your parents?”

“They’re alive. Father, mother, a younger sister. We’re one station away from here.”

“Then why here?”

“Various reasons.”

“Tea is ready, here you go—!”

Kaori brewed green tea with practiced ease, setting three cups. Just before she could say “Please, help yourself,”

“Hey, weren’t you just barging in?”

“Doesn’t matter, just keep this a secret.”

Not revealing about this place was an established premise. Meanwhile, asking what intrigued her most:

“By the way, this room is ridiculous. Is there a reason?”

Yuzuno asked, eyes on the countless subculture items.

“I enjoy escaping reality.”

Risome responded dreamily. Oh, she thought, makes sense.

“Does Sakasaka also like these things?”

“Well... Running a newspaper, I must have broad knowledge. Honestly, I, Kaori, kind of find it okay.”

“What…”

“Then a question from me.”

Risome sipped his tea and stared at Yuzuno:

“You witnessed the crime during club training, became the first to find the body, then controlled by police and questioned. Yet, you broke free to reach here. Why?”

Yuzuno was stunned beyond belief, unable to answer.

“You- you knew? You knew I found it first? You knew I ran from the police?”

“It’s nothing. Just a guess.”

“But you know in such detail, how…”

“Shoes.”

Showing a bored expression, Risome indicated with his teacup toward the door. Yuzuno glanced back to see her shoes—Mizuno's table tennis shoes—on the concrete floor.

“You’re in table tennis shoes. They’re worn in gyms. The girls' team practices in the old gym, so you were there, and still haven’t changed. 

If you were in the old gym then, you happened to be at the crime scene. As you still have table tennis shoes on, it means you were immediately held by police. Considering this, you came here right after. Were you released? No, if officially released, you'd have changed shoes. You still wearing table tennis shoes implies you excused yourself to escape amid questioning. Suggesting you aren’t suspected. 

If you aren't a suspect, you were questioned and got caught in a murder. Such a person, I presume, is the first to discover the body.”

“…”

Yuzuno didn’t move, holding her teacup. After a moment, she regained awareness of the heat on her fingertips.

What was that just now?

Shoes? With just a glance at the casually tossed shoes, he pieced together so much. He understood Yuzuno was caught in a murder, realized she'd fled police questioning, and knew she wasn’t the suspect.

Moreover, he hadn’t shown a hint of thought since she entered. If anything… just that moment when, after Yuzuno’s intro, he shifted his gaze slightly and frowned. Could it be, from noticing the table tennis shoes, to a slight frown within seconds, he “guessed” everything?

No way!—thought Yuzuno. However, the explanation was sound and clear, an idea formed as her scrambled mind processed it.

—This guy’s the real deal.

“That’s right, I came to ask for Risome’s help!”

Yuzuno moved closer to Risome, earnestly declaring.

“That reminds me, you said that. Why the case is my problem?”

“Do you know Sugawa, the table tennis team captain?”

“Oh, maybe I do, maybe I don’t.”
"I know!" Kaori raised her hand and said, "I know her. Actually, we're friends. What's happened to Nao?"

"She's going to be treated as a suspect!"

"What? What's going on?"

"I want to stop the police from doing that. But there's nothing I can do alone. So, I thought maybe Risome-kun could help..."

"Why are you coming to me?"

"I heard you're exceptionally smart. And you score full marks in all exam subjects..."

"You see, that's exactly why I don't want to help!" Risome said to Kaori with a displeased expression. What's going on here? No, at this point, it doesn't matter. Whether it's his evasive answers or his strange behavior living in the clubroom, and the peculiar hobbies that filled the walls, none of that matters. What's important is his mind.

"Risome-kun is the only one I can rely on! Please help Sugawa-san!"

"I won't!"

Yuzuno's earnest plea was entirely deflated by those three words. She couldn't help but lower her head, almost burying it into a small mountain of DVDs.

"Why?"

"Yeah, why don't you help her?"

"Why must I help Sugawa? If the police say she's the criminal, could they be wrong?"

"But Sugawa couldn't possibly be the culprit!"

"Yeah, yeah. Nao is a very serious person!"

"Then, you can face the camera and say, 'She's usually a good person'!" Risome responded sarcastically, then stood up with a magazine in hand.

"Alright, go back. Even though I seem like this, I'm actually a busy person. I need to finish reading this week's 'Despair Teacher', admire little Yuu's bandage, and then I need to go buy dinner!"

"What did you say?"

"Yeah, Risome. Don't you always say little Churu is cuter?"

"No, no, Kaori-kun, that's not what I'm talking about..."

What should I do? In this silly back-and-forth, Yuzuno's mind was racing at full speed. It was rare to meet him so easily, and he was this reliable. If things kept going this way, our last hope of rescuing the captain would disappear. Simply pleading isn't effective. Is there an exchange condition? Threaten him by exposing that he lives in the clubroom? No, no, I don't have the courage to threaten, and I have a feeling that if I use coercion, this guy will just go through the motions. I need more positive terms. Positive and something that makes him agree naturally—

A flash of inspiration struck her.

"Risome-kun—" Yuzuno called out to him. Risome had already lain back on his bed and started flipping through magazines. Hm?—he responded half-heartedly.

"You just said you need to go buy dinner. So what do you live off, Risome-kun?"

"...live off?"

"Even though you live alone at school, it's kind of like living independently. Where do your living expenses come from? Do you work?"

"This has nothing to do with you." Risome replied, burying his head in the magazine. It seems he doesn't have a job after all.

"Your parents give you the money, right?"

"......"

"Yes, that's how it is." Kaori answered for the silent Risome.

"But I'm afraid your parents wouldn't agree with you living here, right?"

"......"

"Well, generally no parent would agree." Kaori answered again.

"Oh—? So Risome-kun's parents have to give their son living in the school clubroom, who left home without permission, some money every month?"

"What are you getting at?" Risome lifted his head from the magazine and looked coldly at Yuzuno. It seemed promising.

"Risome-kun, don't you feel embarrassed? With one hand defying your parents, and with the other hand relying on them. This situation is too indecisive and incomplete. You should earn your own money!"

Risome slammed the magazine onto the pillow, then slowly got out of bed. He clenched his right hand into a fist, pressing it firmly down on his trembling left hand as if suppressing an impulse, otherwise, he would have hit Yuzuno hard.

"You...!"

"I'll pay you!"

"Huh?"

The semi-independent boy suddenly froze.

"If you're willing to help Sugawa-san, I'll pay you. The whole table tennis team will pool together and pay you 100,000 yen. How about it?"

"......"

This proposal mixed carrot and stick, very effectively.

The two stared at each other for a moment. Within Risome's mind, living expenses, pride, and this week's 'Despair Teacher' were swaying on a balance.

Soon, he loosened his tightly clenched right fist, slowly lowered his hand, and murmured word by word, "100,000 yen, huh." It seemed Yuzuno had won this battle.

He moved closer again and sat at the low table.

Risome Tama cleared his throat, regaining the room's master's dignity, then intertwined his fingers and slowly said, "So, tell me the details."

"...Oh." Risome casually responded after Yuzuno reported all the information she had.

"Speaking of, you're really lucky. If your brother wasn't a detective, with the way you eavesdrop, wouldn't that cause big trouble?"

"Yeah...that's not what I meant. What do you think of the case?"

Perhaps at this moment, the captain was about to be handcuffed. Yuzuno hurriedly pressed him for a conclusion.

Kaori, who had been taking notes, softly said, "The culprit must be Nao, right?"

"What are you talking about?"

"See, it's a closed room behind the stage. Given the situation, the only one with a chance to commit the crime is Nao."

"What does Risome-kun think?"

"Huh? Well—"

Risome pondered while chewing a rice cracker that came with the tea.

"Let me ask a question. You mentioned there was an umbrella in the men's bathroom, right? Soaked in water."

"Yes."

Right now, more than the umbrella, I hope you'll talk about the captain Sugawa.

"That umbrella must be a man's umbrella, right? If a woman's umbrella appeared in the men's bathroom, it would be even more puzzling."

"Yes, it's a black long-handled umbrella. Don't know whose it is."

Yuzuno recalled the time before her brother and the investigators arrived, when the students were waiting in the classroom. Detective Shirato showed them photos of the bow tie and the umbrella, asking if anyone recognized them. The related individuals were all gathered in the classroom, but no one raised their hand.

"However, this umbrella wasn't there when lunch break ended, correct?"

"Yes, the detectives said the janitor testified to that."

"Was the umbrella damaged in any way?"

"No, it's almost brand new."

"Oh—"

Risome started crunching on another rice cracker. After finishing one piece, he addressed the school newspaper president, "Kaori, as compensation for not locking the door, could you go to the office? There's something I need you to confirm."

"What is it?"

"Check if any student was late for class after lunch break today."

"Not in the morning? After lunch break? Why would anyone come to school then? And it was raining heavily."

"That's what I thought too. But just to be sure, check it out. The teachers should still be in the office, go ask."

"I can do that... but the moment I walk into the office, I'll get a stern talking-to again."

"Just make up a quick excuse to brush it off."

"Your suggestion is too careless! Whatever, no point in arguing with you. Fine, I'll go right away."

Kaori slipped her notebook into her chest pocket and left the room. This time, she followed the instructions and firmly locked the door with a click. It seemed she had a spare key.

Once again, it was just her and Risome in the room.

Risome unhurriedly drank the remaining tea from his cup. Yuzuno pondered to herself, "What's with the umbrella? What was the point of the task he just gave Kaori?"

"... So, did you discover anything?"

Yuzuno cautiously questioned. Risome lazily stood up and said:

"It feels like I discovered something, but also like I haven't uncovered anything. However, what I can be certain of is..."

He concluded:

"Your brother is a big fool."

3 The Logic of the Black Umbrella

She immediately guessed which classroom her brother and the others were gathered in. Just next to the classroom where Yuzuno and her group assembled, a stern-looking officer was standing guard.

As Risome approached him unceremoniously and rashly, the officer was startled, his stiff facial expression abruptly vanished, and he asked:

"Hey! What are you doing?"

"Are detectives Sendou and Hakata from the prefectural police inside?"

"How do you know the chief detectives' names..."

"Come on, let me in. I have something incredibly important to tell them."

"Well, but..."

This officer was, of course, hesitant. His wandering gaze caught sight of Yuzuno.

"Oh! Wait! Aren't you the eyewitness? Where have you been? You can't just leave without permission!"

"Don't worry about me, just let him in quickly!"

"Huh? But we're currently questioning significant persons of interest..."

Significant persons of interest. Needless to say, he meant Captain Sugawa.

Yuzuno no longer cared about the surrounding situation. She ran to the door, and even before the officer could stop her, she had already burst in.

This room, originally meant for entrance and career guidance, had a face-to-face arrangement of cheap-looking sofas and tables, just like a reception room would. In seats usually for teachers sat two detectives, while a girl sat opposite them, with her shoulders hunched and her head lowered.

That girl was Captain Sugawa, who was vastly different from her usual self.

"Yuzu-Yuzuno!"

Her brother was the first one to stand up.

"What are you doing? You can't come in here!"

But Yuzuno paid him no heed.

"Captain Sugawa, are you alright?"

"Hakata... what's happening?"

The captain's eyes seemed vacant. It was evident that the police were pressuring her to speak. Yuzuno was on the verge of tears again.

"Brother, you're too cruel, doing such a thing! Release Sugawa-san now!"

"Not, not, it's like this..."

"Hakata-kun, please restrain yourself!"

Sendou, unable to bear it any longer, shouted coldly and furiously.

"This girl, Nao Sugawa, is now a suspect in this major case. If you continue to interfere, I'll detain you for obstructing justice!"

"But..."

"Listen carefully, this is for your own good. Alright, please leave now, stay put..."

"That's for us to say!"

A calm yet undeniable voice came from behind them.

It was unclear how Risome managed to shake off the officer outside, but he was leaning against the door. Of course, the detectives responded with, "Who are you?"

"Pleasure to meet you, I'm Risome Tama." 

"I don't care what your name is. You, being unrelated, can't just come in here! Out!"

"If I don't leave, will you warn me for obstructing justice? 'For my own good'? That's laughable. Detective, you've got it wrong. We're the ones doing you a favor!"

"...What?"

Facing the fearless Risome, Sendou's momentum seemed to falter.

"Listen closely, Detective—uh, may I call you Detective Sendou? If you don't listen now, the prefectural police will make a huge blunder, unprecedented! Accusing an innocent young girl and ruining her bright future. This isn't good for anyone."

"...What do you mean?"

"I mean Nao Sugawa is not only not the culprit but also the furthest from being one. I can prove that."

"Risome-kun..."

The captain called his name as if he were a savior. Yuzuno felt the same.

Of course, that rested on the assumption that Risome's subsequent explanation would convince the police.

Since they had just left the activity room and come here—Risome had received Kaori's call en route, confirming no one was late after the lunch break—Yuzuno hadn't yet heard Risome's reasoning. Although he seemed confident, Yuzuno couldn’t help but feel uneasy inside.

"...Did you witness any situation related to the case?"

"No. At the time of the incident, I was in the classroom discussing 'Armored Trooper Votoms' with the school newspaper president, so I didn’t see anything. Besides, I just heard the details from her."

Risome pointed at Yuzuno. Her brother glared at her: "What on earth are you doing?" Unable to explain, Yuzuno could only hurriedly avoid her brother's gaze.

"So you mean, just by hearing the briefing, you inferred she’s innocent?"

"This should be reversed. You heard the briefing, saw the scene, and spoke with the witness, yet you still didn’t discover her innocence."

Sendou, intending to mock Risome, was instead shamed by him. The detective frowned.

"...Alright. Since you’ve put it that way, we’ll listen to what you have to say. Hakata, take some notes."

"Huh? Detective Sendou, are you serious?"

"Listening to him won't lose us anything. You’re Risome, right? Go ahead. Tell us why you think Sugawa-san isn’t the culprit."

Sendou urged provocatively. His gaze was sharp, as if facing a genuine criminal. It also seemed to say: I won’t let any vague arguments pass.

But Risome showed no fear.

Resolutely, he sat beside Captain Sugawa, adjusting his sightline level, looking directly at the detectives, then answered crisply:

"I think so because there's an umbrella in the men’s bathroom backstage."

"An umbrella?"

Sendou retorted, looking toward the room’s end.

Following his gaze, Yuzuno noticed the table at the corner with the remainings from the scene. Among the numerous scattered items, the black umbrella was particularly conspicuous.

"What about that umbrella?"

"The umbrella itself has no problem. The issue is why it’s in such a place?"

"It must be someone’s forgotten item."

"Do you think so? Perhaps you think leaving an umbrella in the bathroom is quite usual. But that place isn’t a station or a family restaurant bathroom; it’s the school gymnasium’s bathroom."

"...I don't understand your point."

Risome sighed lightly and said:

"Alright, let's assume, for now, that the umbrella is 'something someone forgot to take’. First, this person used the bathroom after the fifth period. This is clear because the janitor said he didn’t see the umbrella at the lunch break's end."

"Mm."

"In other words, someone used the bathroom after the fifth period. No, to be more precise, from the start of the fifth period to the end of the sixth period, around three o’clock. Because Sugawa-san and the others arrived at the gym by three, if someone went to the bathroom, they should have seen it."

"Mm... indeed so."

Other than the corridor, the other entrances were locked, so to go to the bathroom after three, one had to pass before the captain and them.

"Someone used the bathroom from the fifth period to three o’clock dismissal, leaving the umbrella behind—a major premise. But if that's so, strange facts will arise."

"Strange facts?"

"First, this person brought an umbrella."

"...Why's that strange? Isn't it raining today?"

"No, this is very odd. Hey, Hakata’s sister!"

Risome suddenly turned his head. Yuzuno was caught off guard by his calling, reflexively raising her volume, "Yes! Here!"

"You, in your entire campus life so far, have you ever brought an umbrella to the bathroom during school hours?"

"Huh? Hmm."

What’s this got to do with Sugawa-san?—Yuzuno complained inwardly while contemplating this question. Elementary school, middle school, and now high school. In nine years and over two months of school life, bringing an umbrella to the bathroom during class hours, such a scenario—

"...No."
"As soon as I get to school, I always put my umbrella in the classroom umbrella stand.” Risome seemed very satisfied with her answer. He turned back to the two detectives and said:

“She’s not wrong. Students entering the school building definitely put their umbrellas in the umbrella stand and wouldn’t be walking around all over with them. After school is another matter, but during class time—it’s a time when there’s no need to go outside, really—it’s unreasonable to carry an umbrella to the bathroom. Moreover, everyone knows without me saying that there’s a covered corridor between the old gym and the school building.”

“There is no need to use an umbrella when walking through the corridor…” My brother murmured. Sendou concluded, “That means that during this time, a student using an umbrella to go to the gym is very unnatural.”

“That’s right.” Risome nodded.

“That being said, however, not all students attend class obediently. So, let’s consider whether there’s an exception. That is, someone wandering around campus with an umbrella during class time.

“The first that comes to mind are students who are late or leave early. If someone is entering or leaving school from noon until after school, then using an umbrella is reasonable.”

“…When first entering or just leaving the school building, they would definitely have an umbrella…indeed.” My brother stammered in agreement.

“However, those who were late can be excluded. Based on what we learned from the office, no students came in late after lunch today.”

“Really?”

“If you doubt it, please check yourself.” Risome pointed to the intercom phone on the wall. My brother hesitated for a moment, then stood up to call the office. The information was confirmed promptly, and he nodded to his superior, saying:

“There were indeed no latecomers after lunch.”

“I see.”

“However, they told me something strange. Apparently, a girl just asked about this as well…”

“Let’s get back to the main subject!” The person who dispatched the girl purposely shouted loudly.

“No students were late. That means that the only students who might have been walking with an umbrella from noon until after school are the ones who left early. Incidentally, students from class 2-4 who finished class early can also be counted as leaving early.”

At the mention of her class, Captain Sugawa, who had been dumbly listening to their conversation, shivered. Unfazed, Risome continued without pause:

“And then there are people other than students. Like school faculty and members of the parent-teacher association. There’s also the possibility that someone unrelated to the school used the restroom without permission.”

“Are you saying a suspicious person broke into the gym?”

“That’s roughly what I’m suggesting.”

“…Alright, let’s not dwell on that for now. Continue.”

“I’ll summarize. The possibilities include students who left early, students from class 2-4, faculty members, or suspicious individuals. Only these four groups could have left an umbrella in that bathroom. No problem so far, right?”

“…That seems reasonable.” Sendou nodded. It appeared that his attitude toward Risome had become much more serious and earnest since the start.

“Now then, based on these conditions, let me talk about another odd fact. It's the location of the restroom.”

“Location?”

“The old gym’s restroom is in a complex location. You have to go through the hallway at the end of the school building, cross the gym, enter the backstage area, and then go past a doorway to get there. It’s not a place you can rush to impulsively. Moreover, it’s dirty and dilapidated. The floor is still wet right now. Of course, those having classes in the old gym would typically use it. But, as mentioned earlier, carrying an umbrella is unnecessary even then. So, considering that, why would someone specifically go to the restroom in the old gym when there are other restrooms available in the school building?”

Risome paused.

Sendou crossed his arms over his chest, pondered quietly for a moment, and then spoke:

“Perhaps the restroom this person intended to use was occupied in every stall. So they went to this inconvenient but less crowded restroom.”

“That’s exactly right, Detective!” Risome smiled, as if he had been waiting for this response.

“Because other restrooms were unavailable. The only reason to use the old gym restroom that I can think of is this. But even using the earlier deduction, it would have to be a student leaving early, a 2-4 class student, faculty, or a suspicious person. Regarding faculty and guests, as in many high schools, this school has dedicated restrooms, which would not be completely occupied. Also, when class 2-4 dismissed, the other classes were still in session. In such a case, any restroom should still be empty. Therefore, it is unlikely that faculty or students from class 2-4 would use the old gym’s restroom.”

"…Ah."

“Next, let's consider students leaving early. If someone left during class, the situation is similar to class 2-4. The restrooms wouldn’t be fully occupied during class. So…”

“During the break between classes.” The inspector interrupted Risome.

“Even before school is dismissed, that doesn’t mean everyone is in class. There’s usually a short break between fifth and sixth periods, isn’t there? If someone were leaving early during that time, it wouldn’t be strange for nearby restrooms to be full.”

“Good point!” Risome cheered up.

“However, if you follow this hypothesis, the situation becomes like this: this person left after fifth period. They packed their things, took out their umbrella from the stand, planning to leave school, but on the way felt the need to use the restroom. Finding nearby restrooms full due to a class break, they went to the old gym’s restroom for relief. This person, having relaxed, left the umbrella in the restroom and went home… How about it, Detective?”

“Makes sense.”

“Really?” Risome asked with a hint of provocation, making Sendou’s face twist in annoyance, “Is there a problem?”

“There is a major problem! Look, how did this person get home in the rain without an umbrella?”

"…Ah!" The two detectives looked at each other in dismay.

Risome smiled as he enjoyed the sight before saying with an exaggerated air, “Now, do you understand?”

“Hypothetically speaking, let’s say a student used the gym’s restroom under the circumstances mentioned and left the umbrella there. Even during the class break after fifth period, it was still pouring rain. Forgetting an umbrella while planning to go out is unlikely. The student would have realized immediately upon exiting the old gym, gone back to retrieve it, and the umbrella would not have been left in the restroom by the time school ended.”

Risome pointed to the almost new umbrella on the long table, adding, “Besides, this umbrella is practically new. It’s not the kind you just discard easily like an old plastic one. Therefore, we can eliminate the possibility that it was left by a student leaving early. Which leaves us with…”

“A suspicious individual!” The inspector shouted again to save face.

“An unrelated person sneaked into the school and used the restroom without permission. Given that the school building had many people, using the old gym’s restroom wouldn’t seem unusual.”

“But, but Officer Sendou, the cameras at the main gate and the north gate didn’t capture any suspicious individuals entering or exiting the campus…”

“They might have used the back gate. There are footprints as evidence. Or they could have climbed over the wall…”

“The wall? The school’s walls are very high to prevent balls from going over. I think climbing them would be impossible. However, the back gate is indeed a route.” Risome interjected, almost as if he were already part of the investigation team. Then he added out of boredom, “But where they entered doesn’t change the deduction.”

“What do you mean?” Sendou asked.

“Detective, I heard the incident occurred around 3:15. And within five minutes, the police were there. Were there any reports of suspicious individuals found on the campus during the initial investigation?”

“There were none…”

“Then, the suspicious person would have left school by the latest at 3:20 or 3:30. Yet, it rained continuously until after 4:00.”

“…” The detectives once again found themselves speechless.

“It’s the same logic for early-leaving students. Whoever it was, if they left the building before the rain stopped, they couldn’t have left the umbrella in such a place. So, the last possibility—that a suspicious person used the restroom—also disappears.”

Risome took a brief pause. He picked up a pencil from the penholder, playing with it as he continued, “Among those who might have taken an umbrella into the restroom, half couldn’t use the gym’s, and the other half wouldn’t have forgotten to bring the umbrella out if they did. Therefore, no matter how you look at it, that umbrella couldn’t have just been left there by someone.”

The initial assumption was completely overturned.

If it wasn’t an item left behind, then it was—

“In conclusion, we can say that someone deliberately placed that umbrella there. I don’t know their intentions. But despite a murder occurring there afterward and a schoolwide broadcast notifying everyone that there had been an incident at the old gym, the owner of the umbrella has yet to come forward. This implies that the person who left the umbrella has a significant connection to the crime and, due to hidden motives, cannot openly come forward—hence, the umbrella’s owner is the real culprit.

“Then, what kind of person is the umbrella’s owner? I’m unclear on the details, but since they left the umbrella in a men's restroom, the gender is at least apparent.”

“…”

“Let me ask this: up till now, have you been questioning male students or female students?”

“Indeed.” After a long thought, Sendou spoke heavily.

“Your reasoning is interesting. An umbrella left in such a place is certainly a fact worth paying attention to. We were also somewhat suspicious when we found no fingerprints on the umbrella.”

“Thank you for the compliment.”

“According to your deduction, the culprit is a male. Therefore, Nao Sugawa, being female, could not possibly be the culprit.”

“That’s correct.”

“However, if that’s all, doesn’t that mean ‘proven completed’?”

The pencil no longer spun in Risome’s fingers and fell onto the desk.

“Why?” Risome asked calmly, as Sendou’s eyes searched for a counterargument.

“First, you are ignoring other factors too much. For example, the crime scene was a locked room. If there’s another person who left the umbrella, how did they commit the crime?”

“There are countless ways to break a locked room; they're as numerous as soil on Earth, enough to grow a forest.”

“It’s not good to sidestep the issue like that.” Sendou glared at Risome. His current attitude was very different from when he was questioning Yuzuno and Sanae earlier. His gentle words hid sharp hooks.

“And there’s another issue… Leaving a man’s umbrella in the men’s restroom, meaning the culprit is male—that explanation is too rash. In expert terms, it’s careless.”

“Do you have another explanation?”

“Yes. According to this explanation, the mystery of the locked room would be solved in an instant. Want to hear it?” The hooks seemed to hover around Risome’s neck. He urged him to speak, and the inspector began to elaborate on his theory:

“The culprit is female. She purposely left behind a men’s umbrella.”

“…”

“In other words, there was no male involved from the start. The umbrella was left by Nao Sugawa as a disguise.”

“What?”

Yuzuno didn’t immediately grasp the meaning of this statement.

“No way…”

“That’s correct. Nao Sugawa placed the umbrella in the men’s restroom to make it look as if someone else committed the crime. When she entered the gym…she didn’t bring large luggage. So she hid the umbrella in the backstage before, right after lunch. If she did all this, the locked room status wouldn’t seem contradictory. The reason there are no fingerprints on the umbrella is also found. How could something meant as a guise have her fingerprints on it?”

“I didn’t do such a thing!”

“Well, what do you think of my deduction, Risome-kun?” Captain firmly denied this, but the inspector acted oblivious. Risome’s earlier proud face dimmed, his expression now blank.

“What do you think? I believe this is a reasonable deduction. Would you give your opinion?”

Yuzuno panicked.

Not good, the reasoning made to rescue the captain was thoroughly overturned. According to Sendou’s deduction just now, the mystery of the umbrella and the locked room were all solved. And at the center of the vortex was Captain Sugawa.

She glanced at the captain. Once hopeful but again plunged into despair, her dejection was increasingly obvious. No, perhaps Yuzuno’s expression was also like this. Ultimately, the current situation was caused by her.

All that could be done now was to cry and plead. Just as Yuzuno planned to slide over to her brother’s side, she heard Risome, who’d remained silent, speak again:

“You're admitting that on the basis of my correct deduction—in acknowledging the extraordinary reason for an umbrella’s presence in a men’s restroom, likely placed there by the culprit—you are deducting, then, that the umbrella was Sugawa Nao’s guise, right?”

“Yes, that’s correct.”

Smiling as if in triumph, Sendou wore a victorious smile that clearly etched across his face.

But then—

“Well, I’ve already proven that Sugawa Nao couldn’t possibly be the culprit.”

“…What?”

Not only Sendou was caught with a victorious smile.

“What are you saying? What was proven was that Sugawa Nao is the culprit…”

“No, it’s the opposite. What’s proven is that Sugawa Nao couldn’t be the culprit.”

“Why?”

“Because she testified that she ‘saw a girl enter the backstage.’”

The pause was slightly protracted.

"…Ah!" The detectives exclaimed once again in unison.

“Indeed, please think carefully. Listen up, Sugawa stated she saw a girl entering the backstage. Isn’t this strange? If she left a black umbrella in the men’s restroom, wouldn’t she have said she saw a boy entering instead? Otherwise, the guise lacks consistency and eventually loses its purpose.”

“No, no, but…”

Now it was Sendou’s turn to get anxious.

“Is there anything left to say? Planning to appear male with an umbrella, but claiming to have seen a female—it’s simply impossible. That means she wasn’t the one who left the umbrella there. Hence, someone else did, and he’s the culprit. In conclusion, Nao Sugawa isn’t the culprit.”

“I’m done.” Risome made his closing arguments. Sendou wasn’t willing to give up yet:

“Maybe she did so on purpose! She’s the culprit, deliberately providing contradictory testimony to disrupt the investigation…”

“Ah, I see. So she anticipated that her disguise would be seen through, and intentionally said she ‘saw a girl.’ Is that right?”

“Yes!”

“And she never pointed out this contradiction, even when near arrest. For a smart crime, that’s too foolish.”

“This…”

“Well, how about this, detective.” Risome continued with a tone like teaching a misbehaving child: “I’ve logically derived the strangeness of the umbrella being left in the gym restroom.”
"You acknowledged this point. Then, you yourself said that the umbrella could very well be the criminal's disguise. I also agree with your viewpoint. To explain such an anomaly, that's the only way. Moreover, if this is indeed a disguise, then Nao Sugawa cannot possibly be the murderer. This is a fact that anyone can see. Isn't that right, brother?"

"Huh? Oh, oh. I suppose so..." Her brother responded, tilting his head while pondering something. He was probably thinking about why the person was calling him "brother."

"Yes. According to my expectations, the girl Nao saw truly exists. The black umbrella must be her disguise. That's the only way it makes sense. As for how she disappeared from the locked room, I haven't figured that part out..."

"Yes, that's it, the locked room!" Sendo shouted loudly. A layer of greasy sweat appeared on his forehead.

"Your reasoning doesn't explain the locked room. In a situation where no one could leave, aside from her, no one else could have committed the crime!"

"But this locked room precisely supports my earlier conclusion."

"W-what?"

"If Nao Sugawa were the murderer, why would the scene still remain in a locked room state?"

"……"

Sendo was dumbfounded, the sharpness in his eyes completely vanished. Yuzuno, who was eavesdropping on their conversation, also exclaimed softly, "Ah!"

Exactly. Why didn't I think of that?

If the captain had killed Tomoki Asajima, and the backstage remained locked, it would clearly indicate that only she could have committed the crime. Typically, to disguise as someone else's crime, one would open a lock from the inside, or testify to having "seen someone escaping," that would be logical. 

However, the captain did neither of these. Why? Because she wasn't the criminal.

It's an extremely simple yet old contradiction, but it's incredibly powerful as a decisive blow. The expression on the inspector's face looked like he was hit by a barrage of machine-gun fire at the exit of a maze. Her brother was also left speechless, forgetting that he was still taking notes.

"Therefore, to put it in your terms... 'proof complete.'"

Tama Risome leaned back, sinking deeply into the chair, and uttered these words.

---

A Hundred Thousand at Once, an Extension for Fifty Thousand

The rain clouds finally dispersed completely, and through the window, a deep blue sky could be seen, still carrying hints of evening twilight. Although it was the summer solstice season, it was past seven o'clock, and the sun was nearly setting.

In the career counseling room, only Yuzuno, Risome, and Captain Sugawa remained. The detectives were in another room having an emergency discussion. The topic was, of course, "Nao Sugawa's innocence."

Following that, as if a taut string had suddenly snapped, the captain thanked Risome and covered her face with both hands, crying. Even now, she was sitting on the chair, curled up, sobbing quietly. Although Yuzuno knew she was crying tears of joy, the tremendous contrast with the captain's usual image made Yuzuno a little reluctant to face it.

The person who saved her, Risome, had already walked to the window, looking up at the sky gradually being enveloped by night. Yuzuno accompanied her captain, absentmindedly watching this young man.

His reflection appeared in the glass. His right hand rested on the window frame, while his left hand idly in his pocket. The first and second buttons of his shirt were undone while the hem was tucked into his pants, visibly outlining his slender figure. From his expression, it was impossible to tell what he was thinking, his eyes dimmer than the scenery outside.

This young man proved the captain's innocence against the police—[this was what I asked him to do, but it lacks a sense of reality.]

"Um, Risome... thank you!"

Yuzuno thought it was best to express her gratitude first and walked over to Risome.

"Don't forget about the hundred thousand yen!" He said without turning his head. Right, there was such an agreement.

She quickly did some calculations in her head. Currently, the girls' table tennis team had sixteen members, costing about seven thousand yen per person.

"Could you charge a little less?"

"No."

"Well, I thought so too. I'll figure out a way to gather it."

"Do it quickly. I want to buy a set of original drawings from 'Madoka Magica'."

"...Original drawings?"

"Yes. There are several volumes, priced high, so I thought I couldn't afford them, but now it's the perfect opportunity. With a hundred thousand yen, I can buy it easily and even get some books from Comic Market."

Although Yuzuno didn't really understand what he was talking about, it seemed he didn't plan to use this money properly.

"You're not going to use this money for living expenses?"

"This is my living expense."

...Apparently, they had different definitions of living expenses.

Is he impressive, or is he not? Yuzuno felt her initial impression of him was collapsing in her mind.

"It doesn't matter, it's fine. Anyway, thank you very much!"

"You're welcome. It was just a performance."

"Performance?"

The design of the two-stage reasoning, deliberately allowing the other party to take the lead for a time and then leading the other party's reasoning to naturally support his conclusion, thereby turning the tables.

Such a trap set for the police was undoubtedly a jaw-dropping performance.

"I suppose it was lucky that they were convinced. There's actually a loophole in this reasoning."

"Huh? What's the loophole?"

"When a student leaves early, they would return to fetch an umbrella at that instant. There is exactly one student in this school that does not follow this common logic. This student lives on campus and even if they go out without an umbrella, they can return to their room without getting wet."

"Could it be this person is..."

"Me." Risome said expressionlessly.

"But, of course, I didn't leave early."

"...Risome, you're not the murderer, right?"

"Unfortunately, I have an alibi."

He stated the factual alibi. However, the fact that he didn't immediately deny by saying "I'm not the murderer!" was a bit eerie.

"Goodness, I'm beginning to think giving you a hundred thousand yen is ridiculous."

"Don't say that. If you treat me as an exception, the reasoning itself holds! I always thought the umbrella was the criminal's disguise..."

Risome scratched his head and, turning, gazed at the belongings left in the corner of the room, speaking indistinctly, "Huh?"

"...What's wrong?" Yuzuno asked him, but Risome remained motionless. He stared at the long table with the belongings on it, frowning slightly.

"Strange."

"Strange? What's strange?" Yuzuno looked in that direction too. The various belongings were individually placed in plastic bags, accompanied by small labels with the location of discovery scribbled on them.

A napkin in the "victim's left side pants pocket." The student handbook in the "victim's left front chest pocket." A keychain, mobile phone, and wallet in the "right side pants pocket," and something resembling a DVD-R disc in the "right rear pants pocket." So far these were Tomoki Asajima's items, others included a red bowtie for girls and an umbrella. The bowtie was found under the "right side stage staircase," and the umbrella, of course, was found in the "left side men's bathroom."

Is there anything strange here?

"Is it the bowtie?" Yuzuno asked without thinking. Since the umbrella in the bathroom was strange, the bowtie on the side stage also seemed unnatural. Although she had no basis.

"No, not this. I feel the imbalance."

"Imbalance?"

Risome strode over to the long table, squinting while examining the belongings as if selecting items from a market stall.

"Only the napkin is in the left side pants pocket, but the right side has the key, phone, and wallet. Isn't that strange? There should be a limit to being unbalanced."

"Oh, when you put it like that... it does seem so."

Indeed, the right side pocket had more small things, which would be inconvenient to move around if the pocket was stuffed with items.

"Why?" Risome muttered to himself, reaching out his index finger to check every item. Quickly, his hand stopped on the napkin.

"The napkin has blood on it."

"Yes. The student handbook is also stained with blood."

"That much is clear."

"...Sorry."

"Why apologize? Anyway, blood... you mentioned Tomoki's corpse showed signs of having been moved, right?"

"Yes, it seems that's why it was considered homicide rather than suicide."

"Specifically, from where to where was it moved?"

"What?"

Yuzuno tried to recall the snippets of conversation she overheard from the detectives, but she couldn't find an answer. Her brother only mentioned that the corpse was dragged.

"U-uhm. Sorry. I didn't catch the details of that..."

"It was pulled from behind the right side curtain to the center of the stage."

A calm voice rang out from behind.

She turned her head, just in time to meet Captain Sugawa's eyes. The captain had stopped sobbing and wiped away her tears, her spine straight as usual, like on the field, looking energized and unwavering.

This was the usual captain.

"That's what the detectives said when they were interrogating me, suspecting me."

"Pulled out from behind the side curtain."

Risome scratched his chin, completely ignoring Yuzuno's joy at the captain's revival.

"Interesting." He said softly.

"Interesting? Did you discover something?"

"Didn't discover anything. I just thought of something."

"What is it? Tell me!"

"Why should I tell you? Our contract has already ended."

"......"

His indifferent words made Yuzuno fall silent. Right, how could I forget? I hired this boy with money.

"The contract stipulates: I prove Nao Sugawa's innocence, and you pay me a hundred thousand yen."

"A hundred thousand? Hakata, you made such a contract with him?" The captain was astonished, but the situation was not just this. The anxious Yuzuno struggled to hear what Risome was saying amid the chaos.

"And I fulfilled it. If you want me to continue working, you'll have to extend the contract with me. Whether it's at a video store, karaoke, or solving a mystery for someone, extending time costs money."

He placed his right hand lightly in front of Yuzuno, spreading his fingers.

"Five thousand yen?"

"Wrong place value."

"Five hundred yen?"

"Don't joke around. It's fifty thousand yen. If you pay me fifty thousand more, I can keep working until the case is solved."

"Fifty...what?"

What caught Yuzuno's attention was not the amount, but the latter sentence.

"S-solved? You can solve the case?"

"Well." Risome gave a mocking smile, shrugging his shoulders.

"I'll do my best, though. I even thought it through carefully—if the police are here for too long, it will impact my life."

"...So that's the reason?" In other words, since his living arrangement in the activity room might be revealed, he hoped the police would leave quickly.

"What does it matter to you why! Anyway, if I solve the case, I charge a hundred fifty thousand yen, deal?"

"Please do it!" It was Captain Sugawa who called out. 

"Please try, Risome. We'll figure out the money from the table tennis team. Just catch the culprit! They killed Tomoki Asajima and almost got the police to arrest me, I'm beyond angry!"

"I-I beg you too!" Since the captain said so, Yuzuno had no reason to oppose. She bowed too.

If catching the culprit only cost each person nine thousand three hundred seventy-five yen, then it would be too easy—if they could actually catch them.

"Alright, I understand. Extension!" He ended the conversation with a clap of his hands and resumed concentrating on the belongings.

Though the back he presented looked like a reliable, capable private detective, Yuzuno overheard his true thoughts: "With this, I can buy the complete 'Eve's Time' set too."

...Sigh. This person might not be very reliable after all.

Her brother, Yusaku Hakata, returned to the room just as the conversation was wrapping up.

"Nao Sugawa, your suspicion has been cleared."

Fatigued, he announced the news as soon as he opened his mouth. 

"They'll probably have to restart the investigation... We suspected you and apologize!"

Yuzuno felt her anger rising, could simply apologizing suffice for labeling someone as a suspect?

Just as she was about to scold her brother for it, Risome spoke first: 

"Brother, could I have a word?"

"...I've wanted to ask you why you keep calling me 'brother'?"

"I needed to distinguish between you and your sister. If you prefer I use your surname, I can do that."

"What?... Fine, fine. So, what do you want to say?"

"These are the keys brought by Tomoki. Are these for the broadcasting room?"

"Yes."

"Does it include the key to the old gym's broadcasting room?"

"Yeah. It should be the one labeled 'Do not listen' keyring... hey!"

His brother raised his voice because Risome, upon hearing his answer, had wrapped his handkerchief around his hand and took the key out of the bag.

"What are you doing? Don't touch the belongings indiscriminately! Put it back!"

"I won't leave fingerprints."

"That's not the point... hey, where are you going?"

His audacity did not retreat a bit; he passed beside his brother to grab the door handle. Just as he was about to dash out into the hallway, his brother finally managed to grab his shoulder.

"You can't just take it outside! Just what are you trying to do?"

"If I can't take it casually, then please give me your permission. Or does the brother want to accompany me?"

"Where are you going?"

"Where? Since I took the broadcasting room key, of course, I'm going to the broadcasting room. The one at the old gym."

"Broadcasting room? What are you going to do there?"

"What do you think?"

"Huh?"

Risome answered obscurely, then as his shoulders slipped from his brother's grasp, he escaped and dashed out of the room. Left with no choice, his brother shouted "Hey, stop!" while following him out.

"Risome is amazing, not even afraid of the detectives!" Captain Sugawa commented with admiration. Yuzuno echoed her statement with an "Oh," her tone a bit delicate: "I can't quite tell... though I do think he's impressive."

However, to say he's worthy of respect seemed a bit lacking. Alas, she didn't want to destroy the knightly image of him saving the captain, so it was best to keep quiet.

"Ah, I'm going too; it'll be easier for my brother with me there."

"Yeah, you're right. I'm counting on you! Solve the case!"

"Ah... okay!"

Yuzuno responded to the captain's encouraging trust with an unnatural smile and bolted out the door.

What will the actual situation be like?

Can Risome—along with her brother—really solve the case?

---

Investigation of the Broadcasting Room

Yuzuno charged out the door with momentum, but she caught up with her brother more easily than running after them. Risome and her brother were standing in front of an empty classroom next door— the one Yuzuno had just been in, the waiting room.

Her brother noticed his sister approaching, still showing no kindness. But it seemed he was beginning to resign himself and stepped aside, making room for her. Yuzuno calmly positioned herself next to him. The police officer standing guard didn’t say anything, likely either because of her brother’s presence or because he was already fed up with these unyielding high schoolers popping up one after another.

This particular unreasonable high schooler, Risome, stood in the doorway, scanning the entire room with the same gaze he had when examining the belongings earlier. Inside, the situation was unchanged from when Yuzuno was there a moment ago.

To begin with, the only teacher present among the related personnel was Masumura. Sanae in her training outfit. Two male members of the badminton team. Then there was the drama club's four-person group including Kazuya. Sulking in the corner was the girl with blonde hair, referred to by the captain as Nakamura.
The remaining student council president, Akihiro Masaki, and the new face beside him—Chizuru Yatsuhashi, who had provided Yuzuno with information at the entrance and had apparently brought her here after giving Masaki an alibi. 

Everyone was surprised to see Tama Risome suddenly appear and Yuzuno, who had been gone for so long, finally return. Of course, Chizuru, who knew the situation, was not among them. The vice president exchanged a glance with Yuzuno and immediately understood that the captain had been successfully rescued, giving a radiant smile.

"Hakata, where did you go? Isn't this the second-year student Tama Risome?"

"Yuzuno, you came back so late! You worried me to death!"

"Risome, what are you doing here?"

"Isn't this Risome? Are you a witness too?"

Masumura, Sanae, the student council president, and Kazuya Kajiwara asked in unison. But Risome ignored them and directly asked:

"Is there anyone here familiar with the broadcasting room of the old gymnasium?"

The sudden question made the classroom instantly fall silent.

Soon, six people timidly raised their hands—the four members of the drama club and Akihiro Masaki, Chizuru Yatsuhashi.

"The student council and drama club, huh. Well, you guys would have a use for the broadcasting room."

"Sort of. We often use it during assemblies held in the old gym because we need to adjust the microphone volume and such."

"Since the broadcasting room has the audio equipment for drama, we use it frequently."

Masaki and Kajiwara respectively answered, both showing puzzled expressions, not understanding why he was asking this.

"And there's also a video recorder and DVD..."

"What?"

Kajiwara's additional explanation caught Risome's attention.

"Can you watch videos in the gym's broadcasting room?"

"Yeah, there's a TV and player. After we finished stage practice yesterday, we even watched footage of the seniors' performances... Oh no!"

"What happened?"

"Nothing, I just remembered that I think I left the tape in the player."

"... I thought it was something important!"

He furrowed his brows at what seemed to be needless worry.

"Then, Kajiwara can come too. You come with me... Ah, wait a moment!" 

Risome muttered to himself, paused, then turned to his brother and whispered a few words. His brother unhappily opened a notebook, and the two exchanged a couple more sentences, even Yuzuno who was right next to them didn't hear what they were saying.

He turned back to face everyone in the classroom, officially pointing to Kajiwara this time:

"You come with me, I have many questions to ask you."

"Where to?"

"Do you think it's to the vegetable shop? Of course, it's the broadcasting room."

"... Alright, if you say I should go, then I'll go."

"Please wait a moment!"

Just as Kajiwara was about to stand up, someone stopped them again. It was the student council president, Akihiro Masaki.

"Detective... Mr. Hakata, right? I still don't understand the situation, why is Risome here, and why is he acting with you, a detective? If possible, could you please explain?"

It was indeed a reasonable question. The position that should have been occupied by the sharp-eyed detective Sendou had been taken over by a quirky boy of the same grade, at some unknown point. Moreover, though she hadn't had the chance to ask, Yuzuno waiting outside the waiting room was also quite peculiar.

"Oh, well..."

"I called Risome here."

Chizuru Yatsuhashi confidently answered in place of her vague brother.

"Because, you see, he's a detective."

"Detective?"

"Yes. He's here to solve the case, right, Risome?"

"Because I need a living expense."

The detective replied crossly at odds with the statement.

"In any case, that's the situation. Kajiwara, this way."

To avoid further questions, Risome quickly called out Kajiwara and closed the door. As the door slid shut, Yuzuno saw Masaki with a puzzled expression, while Chizuru smiled gleefully.

"Alright, let's head to the gym... Oh, by the way."

Risome asked everyone to wait again and returned to the career guidance room to fetch something. He quickly came out again, this time with a DVD case in his right hand.

"Hey, this is also from the victim’s… why are you taking even that with you?"

"Because I heard that the broadcasting room can play videos."

“Is that your answer?"

"Risome, are you actually a detective? That's so cool!"

The lively group headed towards the gym. Three of the four had no idea why they were going.

"Brother, what were you and Risome talking about?"

As they reached the hallway, Yuzuno casually asked her brother.

"Nothing, he asked me a question, but it wasn’t a big deal. I don’t even know why he asked."

"Is it about the broadcasting room?"

“No."

Detective Hakata glanced at Kajiwara and Risome, who were chatting politely about being detectives, and lowered his voice:

“He asked me if that drama club head… if Kajiwara had an alibi."

Once outside, they saw the sun had already set. The breeze after the rain was slightly cool, and the arms exposed outside their training clothes felt a bit cold. The dilapidated gymnasium stood darkly against the dusky background, seeming more intimidating than usual. Of course, the fact that a murder had occurred inside contributed to that atmosphere.

They opened the door and found several investigators still working on stage. They also cast curious glances at the sudden visitors, but once they recognized the brother, they took it for granted that it was part of the investigation and turned their attention back to their duties.

Risome, unconcerned with these people, strode through the door on the left side of the stage. Yuzuno and the others followed right behind him. When they entered the left side of the stage area, Risome was already ascending the staircase to the second floor.

The sound of four people’s footsteps clattering on the metal stairs reverberated loudly. Upon reaching the second-floor corridor, the broadcasting room was immediately on the left.

Although Yuzuno knew there was such a room, this was actually her first time entering.

“Alright.”

In the dim, narrow corridor, Risome turned to his classmates of the same grade and said:

"Kajiwara, you use the broadcasting room often, right? Do you have a key?"

“No, though we say often, it's actually only before performances. I really don’t have a key; when needed, I borrow it from the office."

“Oh, the student council as well?"

“Yes… is there a problem with that?"

“No. Since there’s no other key, I'll use this one."

Risome inserted Asajima’s key into the lock and opened the door.

When the light came on, a room about four tatami mats in size appeared before them.

Against the wall opposite the door were two tables with a mixing console on top. Around it, headphones, RCA cables, amplifiers, and large CD players cluttered the space, making the room even more cramped.

There were small square windows on the front wall and the right wall. Through the front window, one should be able to see the stage, and from the right side, the entire gymnasium, but for now, the curtains were drawn.

A long table stood in the center of the room, adding to the congestion. Microphones, mic stands, an old tape recorder, a pile of cassettes, and dusty lamps cluttered the top, entirely becoming a place to store small equipment.

Then, against the left wall stood a rusty tall metal shelf, with an old CRT TV on the top, an ancient DVD player on the middle shelf, and an equally old video player on the bottom shelf.

“What antiques.”

Seeing the TV and player, Risome muttered. “They are,” Kajiwara said. “These were originally stored in the broadcasting room of the main school building, but since they got new ones this year, and it was a shame to throw them away, so they moved them here."

“This year… so, before that, these weren’t here?"

“Yes. They were moved here about two months ago. It solved a big problem. Footage taken on stage can be viewed immediately, and seniors' performance records can also be...

Oh, right. The videotape!"

“We’ll deal with that later. Let’s take care of my business first."

Risome dismissed the drama club head and took a step forward towards the iron rack.

He first turned on the TV's main power, and a small text appeared around the edge of the black screen: “Input 1." Then, he reached for the DVD player.

“Hey! Don't touch it without gloves!"

His brother immediately scolded.

“Didn't they already collect fingerprints?”

“They’ve been collected, but… what are you planning to do here?”

“Let’s start with a video viewing meeting.”

Risome murmured ambiguously and pressed the DVD player’s power button.

But it didn't start.

“… Huh?”

“Is the plug not plugged in?”

Kajiwara pointed to the floor by Yuzuno. By the wall were a power outlet and several extension cords.

“These are recently moved-in machines, and usable power slots were all taken, so the VCR and DVD player share one."

"Oh, must be this one then."

Yuzuno crouched down and found two plugs among the tangle of wires, one labeled “DVD” and the other “VCR.” Sure enough, the one plugged in was the “VCR.” Yuzuno unplugged it and switched to the “DVD” plug.

Risome pressed the switch again, “Vroom,” and the sound of the machine quietly working was heard. The DVD player powered on.

“Alright!”

Without saying thanks, Risome didn’t even glance at her as he continued his work. He took the disc left behind in the case, inserted it into the player, and began playback—only for it to not work again.

“Hey, this time it seems the play button isn’t working.”

“Oh, that’s right. The play and pause buttons on this player are very unreliable. You have to use the remote."

“What kind of junk is this? Remote… where is it? Hey, Hakata little sister, the remote!”

“What good is it telling me..."

But Yuzuno didn’t have to do anything; Kajiwara was already reaching for the box on the table, retrieving a square container. A deep green box with red lettering saying “Mingdian·Sakura Yokan.” Opening the lid revealed not confectionaries, but four differently-sized remote controls.

“Unlike the new gym, it's messy here, so the remotes are all stored in this box.”

Then!—Kajiwara tossed one to Risome. Risome said “Thank you!” and pressed a button on the remote.

Finally, the video began to play.

"Lalalaaa~ 'Introduction to Prefectural Hilltop High School'"

“Hello everyone! Thank you all for attending the Hilltop High School introduction meeting, I’m Morinaga, vice head of the broadcasting station. Next, I'll take you on a tour of the campus.”

In front of the courtyard and school building stood a cheerful girl with her hair tied back in a headband, forehead visible—just as she introduced herself, she was the broadcasting station’s vice head Yuko Morinaga—greeting everyone. If the vice head was the star, then the head, Asajima, must be the cameraman.

“Prefectural Hilltop High School adheres to a tradition and freedom-minded school ethos, with a history of one hundred ten years…”

She soon started the school introduction, with scenes transitioning one after another—old black-and-white photos, the current school building, scenes of everyday classrooms, and scenes of going to school. During the club activities promotion, it featured the track team and wind ensemble, as well as photos from the cultural festival and the second-year field trip. The interviews with current students were likely shot recently; a first-year student, whom Yuzuno had seen before, smilingly shared her thoughts: "This is a school filled with many intriguing individuals!" It’s unknown if her statement was intended as positive publicity.

“This is a promotional video for the school introduction.”

“Yeah. During summer break, they hold introduction meetings for exam takers.”

Hearing Yuzuno’s mutters, Kajiwara responded.

“So the broadcasting station does work like this.”

The boy, who had no connection with fulfilling club activities, crossed his arms and showed a face of surprise.

“Rather than the broadcasting station, it’s more Asajima being capable. I heard he’s also trying his hand at filming competitions.”

“Now you should say he ‘tried’.”

“……”

“Morinaga is indeed quite eloquent, like an announcer!”

To ease the tension, Yuzuno reluctantly threw out a topic.

“Yes, indeed. Our drama club wanted her too, because she has a nice voice.”

“Her voice is indeed pleasant. Reminds me of Yuki Matsuoka.”

“...Who is that?”

“Someone who voices Aiko Meno.”

Even after his answer, Yuzuno remained confused.

Soon, as the choir’s singing began, Yuko Morinaga waved goodbye to the audience, and the video ended.

“…And then?”

Her brother’s comment succinctly captured the situation. They’d come to the broadcasting room and watched a video—now what? What was the point?

“Does this relate to the case?”

“It does not.”

Risome answered straightforwardly while removing the DVD, to which Yuzuno and her brother stood side by side—

“Then, why did you do that?”

“Don’t get me wrong. It’s not completely unrelated, it’s a ‘not related’ kind of related. This is quite an important clue!”

“What are you talking about?”

“Don’t worry about it. We have a lot of other matters to investigate.”

After the incomprehensible remarks, Risome moved away from the TV to conduct a formal search of the broadcasting room.

He stuck his head behind the machines, dusted off the cobwebs, opened the curtain of the small window to gaze at the stage, meticulously examined everything on the table, and finally, as if searching for a hidden door, he knocked around the soundproof walls. Yuzuno and the other two stared blankly at his actions.

“Oh right, the tape. Risome, can I take the tape out?”

After a while, as if he just remembered, Kajiwara said to Risome. Risome was contemplating something against the wall, and upon hearing this, he nodded repeatedly.

Kajiwara crouched down beside Yuzuno and switched the plug back to “VCR,” then pressed the VCR’s power button to turn it on. He took the remote from Risome and skillfully pressed two buttons or so. This time, the VCR spat out a VHS tape labeled “Summer Performance '98.”

“Whew, almost got scolded by Matsue again…”

The drama club president expressed fear of the strict first-year member and took the tape. Just then—

“Wait!”

Risome interjected.

His voice was sharp. Kajiwara shrank back and said:

“What, what are you doing? This tape? Isn’t anything suspicious. Otherwise, we could play it right now…”

“No, not the tape. The remote. Is that remote a shared one for both the VCR and DVD player?”

“Huh?”

Kajiwara looked at the object in his right hand and said:

“Yes. Though the players are different, they’re the same manufacturer. You can switch modes using buttons.”

“Modes…”

“Press the DVD button to operate the DVD player, and press the VCR button to operate the VCR. According to Tsudanuma from the broadcasting station, they originally had their own separate remotes, but both broke, and the player’s buttons stopped working too, so they found a compatible one at a secondhand store."

“I see.”

Risome pondered a little longer, then slightly relaxed his lips.

It was his first smile since entering the broadcasting room.

“One more question, about yesterday. You watched a video in here, right? After practicing."

“Yes, yes.”

“Then you forgot to take the tape out and went home. Why did you forget?”

“Why… because it was almost time for the entire school to fully dismiss, I was worried they’d lock the school gates, so I left hurriedly and forgot to take it out.”
"Ah, I see. Thank you."

"...?"

Kazuya Kajiwara wasn't sure what he was plotting, so he increased his vigilance. Seeing this, Tama Risome seemed very pleased. With sleepy eyes half-closed, he left the wall he was leaning on, turned to his brother, and said:

"Brother, the police must have already searched this broadcasting room, right?"

"Yes. I say, your way of calling me..."

"To what extent was the search conducted? Was it thorough and complete?"

"Well, you'd have to ask Officer Shirato about that."

"Oh, here I am, here I am! We searched the entire place."

A hoarse voice rang in their ears. Speak of the devil, it was the very detective from the Hodono Valley police station who poked his head in from outside the door.

"Officer Shirato..."

"Officer Hakata, what are you doing? The chief is furious, saying you took off with a witness without permission."

"No, no, it wasn't me who took them away..."

"Officer Shirato. Are you Officer Shirato?"

Undaunted, Tama Risome stood before the detective.

"Oh? You wouldn't happen to be Risome-san, would you?"

"You know very well! I'm Tama Risome. Nice to meet you."

"Oh, I see. I heard you proved the suspect's innocence? Hmm, interesting kid. Haha."

It seemed he was a nosy detective. He laughed heartily and warmly patted the shoulder of the outsider Risome.

"By the way, Officer Shirato, I have some questions for you, may I?"

"Sure, go ahead."

"How could you, Officer Shirato!"

Ignoring his brother's distressed expression, Risome asked:

"I heard you searched the broadcasting room. To what extent was the search conducted?"

Shirato tilted his large round face and responded:

"Since our main focus was on checking if anyone was hiding there, the search wasn't very detailed. Fingerprints were taken selectively from various locations."

"Did you touch the television or the player?"

"Television? No. The DVDs left behind were watched in other classrooms."

"Is it this one?"

"Yes, it's this one, this one. How did you end up with it? You really surprise me."

Upon seeing the DVD in Risome's hand, Shirato laughed even more heartily. Yuzuno's brother sighed beside her.

"Let's go back," Risome said to his brother.

"Huh? We're leaving already?"

"If you don't want me to leave, I can stay here."

"That's not what I meant, let's go back. We must. But... did you find anything in the end?"

"I discovered a very important piece of information."

He replied with deep meaning, walking cheerfully out of the room past Shirato.

"Hey? A new discovery?" The inspection chief, who didn't understand the situation, asked Kajiwara with eyes glowing with interest.

Kajiwara could only shrug with a troubled face.

Sendou was already waiting for them at the entrance of the gymnasium. He was nervously flicking a lit cigarette. The female table tennis team members wanted to remind him that smoking was prohibited in the gym, but seeing him glaring over, they reconsidered.

"Hakata! What on earth are you doing?"

The chief's shout echoed throughout the gymnasium.

"How dare you take the student out without permission? Are you joking around? Hmm?"

"I-I'm sorry! I tried to stop them, but..."

Kajiwara apologized vehemently. Seeing her family being reprimanded in front of her, Yuzuno felt uncomfortable. However, Sendou quickly shifted his attention to someone else:

"Rieko Nakamura!"

Yuzuno was wondering if there was really a need to be so loud, but she quickly realized why. Next to her, Risome had vanished. Turning her head, she saw he had somehow already stood on the stage.

"Don't push it! Get down immediately! You're obstructing police work, and I'll take you in!"

"Don't be angry, Detective!"

Risome replied loudly from the stage. It seemed he had no intention of coming down.

"Why does the end of your sentences sound like 'Baki'? Oh, no. Baki would only end a sentence with a pause, not an exclamation mark. Did you know that?"

"What are you talking about?"

"It's nothing. By the way, the body was leaning to the left, right?"

"...Huh?"

Sendou asked in response. Only then did Risome step down from the stage.

"I noticed the tape marking the body's position. The upper body leaning against the side panel was slightly tilted to the left. Before being dragged over, when stabbed and fell, it should have been left side down. That's why the blood only flowed to the left half of the body."

"Is there a problem with that?"

"'Is there a problem with that'? Your wording is so casual. This is the starting point of all deduction. No, to go further, it’s about what happened with Asajima-san's belongings that is the starting point of all deduction."

Risome said as he walked closer to Sendou step by step. When Risome reached Yuzuno's side, the chief seemed subdued by his strange confidence and lost much of his momentum.

"...Stop playing detective games. You have nothing to do with this case."

"I'm not a detective. I just want to earn a little bit of money."

"You troublesome kid! Hurry up and go home! Hey, you guys too. That's it for today!"

Sendou extinguished his cigarette on the iron gate, urging Yuzuno and the others. The three high school students were more than happy to be released, bowed slightly, and left the gymnasium. It should be said they were driven out of the gymnasium.

Originally, it would have been best to go home directly, but after reaching the corridor, Risome turned back and, as if reminding, asked the detective:

"By the way, have you searched Asajima-san's home?"

"...I don't need to tell you."

Sendou replied, looking at him as if facing a mortal enemy. But the nosy chief inspector on the side said:

"Not yet. Why?"

"You- you shouldn't say that! Officer Shirato!"

"Asajima-san liked to film, he should have many DVDs at home. Please check carefully if any DVDs are missing."

Even Sendou couldn't help but react to this statement.

"Why?"

"Because the perpetrator should have stolen one of his DVDs."

"...How do you know?"

"It's the result of my detective game."

Risome smiled and retorted sarcastically.

The detectives fell silent, and Risome also stopped speaking, continuing to follow Yuzuno and Kajiwara toward the main school building.

But just then, as if suddenly remembering something, he turned back towards the gymnasium and said:

"Oh, Detective, I forgot to tell you something."

"What is it this time?"

"Smoking is prohibited in the gymnasium! You should pay more attention next time. See you tomorrow!"
### Chapter 3: Used to Identify the Suspect

#### 1. My Sister is So Unfair, It Troubled Me

Beep beep beep beep beep beep beep beep. The sharp sound of the alarm that wouldn't stop unless turned off pulled Yusaku Hakata from his dream world to reality.

"Ugh—"

Looking at the clock, it was 6:30. He had come home disoriented and crashed into bed at 3 AM. Having not slept for even four hours, he was still quite exhausted, and his legs felt weak as he got up.

Yet, even though his mind was not fully awake, as a detective with the Kanagawa Prefectural Police's investigation division, he found himself still mulling over yesterday's investigation in his half-awake state while changing his shirt.

After that annoying student named Tama Risome left, Hakata and his colleagues (who had been scolded by Sendou to not act without orders) went to Tomoki Asajima's house. With some effort, they got permission from the deeply affected family members and searched Asajima's room, only to find nothing valuable. There was no suicide note, nor anything indicating he had any conflicts or was in trouble, just as the testimony from his sisters suggested. Asajima appeared to be quite a serious student.

However, as expected of the head of the broadcasting station, his interest in filming was far beyond the average person. On the bookshelves in his room, instead of books, were hundreds of DVDs. Two-thirds were commercially available movies and TV shows, while the remaining third were his own works, such as family events. He also took his video camera with him when going out, recording anything of interest. At that moment, among his belongings stored in the classroom alongside his umbrella, was an amateur-level camera with professional aspirations. It was said to be in a black case and well-maintained.

Perhaps heeding Risome's advice, the police chief focused the investigation on the DVDs. Fortunately, the meticulous Asajima had recorded notes on both bought DVDs and personally burned discs, so as long as they took the time, they could identify them with ease. Sendou perused the record book and ominously warned, "The investigators need to work nonstop through the night."

As of this moment, the investigation had not made much progress. The suspect was not identified, the reason Asajima was in the gymnasium was still unknown, and the mystery of the locked room remained unsolved.

It wasn't until their return to the Hodono Valley Police Station that they found important evidence.

Under the morning sun, Hakata squinted, put on his suit, and pulled out a notebook from his front pocket. He opened it to the most recent entry, reading aloud the notes he had jotted down last night.

"On the 27th, 3:10, old gym. Lower the curtains, unlock the door on the right side stage..."

This was after they returned to the station. After a brief formal break, Sendou and the others brought together the forensic team and local detectives, holding a plain report meeting at the table before the formal investigation conference.

"A significant number of fingerprints were collected from the gym. However, as it's a common area for students, this is only to be expected. Narrowing down the suspect's prints from this is extremely difficult."

"Since no fingerprints were found on the knife, it's highly probable that the killer wore gloves during the act."

Unlike Shirato's subordinate who remains uptight, his straightforward tone sees him cutting to the chase.

"As for the blood?"

"All the blood found at the scene and on the abandoned items belonged to Asajima. Besides that, no traces of blood being wiped away were discovered on site."

"Where did the weapon come from?"

"We don't know which store it was bought from, and the bow tie found on the side stage yielded no clues either. The same goes for the umbrella."

At the mention of the umbrella, Sendou's brow flinched for a moment, perhaps recalling some unpleasant memory.

"Did you check the attendance records concerning umbrellas?"

"Feng no Oka High School had no students leave early today. Several students were late, but they all arrived in the morning."

Another aspect supporting Risome's reasoning.

"What about the surveillance cameras? Did they capture the owner of the umbrella?"

"In the morning, several students were seen with similar black umbrellas, but they were all male students. However, from the surveillance footage, the images aren't clear enough to confirm whether it was that particular umbrella. Also, the students' faces were obscured by the umbrellas, so..."

"Never mind, I wasn't expecting much anyway."

Even the unyielding chief seemed dejected at this point.

"Any other reports? Anything to make you grateful that there are security cameras in this world?"

"No suspicious persons were recorded entering or leaving the campus all day. As for vehicles, aside from staff vehicles and our patrol cars, no others entered the grounds."

"Is that all?"

"…Sorry."

"It's not your fault. Alright? Next."

Sendou prompted, and the forensic team's investigator began reporting on Asajima's belongings.

In the wallet, there were about eight thousand yen in cash and a commuter pass, along with some point cards. No signs of missing items. No suspicious emails were found on his phone, and only Asajima's fingerprints were detected on the keychain and tissues. They also added:

"We've removed the bloodstains from the student handbook in his front pocket..."

After chemical treatment, the red had lightened significantly, revealing neat ballpoint pen notes:

"27th, 3:10, old gym, lower the curtain afterwards, unlock the door on the right side stage."

The 27th, today, the day of the incident. 3:10 undoubtedly referred to the afternoon, and as for the gym...

"In other words, Asajima's trip there was pre-planned."

Sendou groaned, and the investigator holding the notebook nodded in agreement, seemingly so.

"However, that's the only record for today. Moreover, the handwriting was indeed that of the victim."

"When was this entry made then..."

"Based on the context, probably about five days ago."

"…I see."

"What piques my curiosity is the phrase, 'unlock the door on the right side stage.'"

Hakata interjected.

"A door with a lock on the right side stage, that would surely be the side stage's external entrance, not including the restroom. If Asajima personally unlocked that door..."

"Then half of the locked room mystery is solved."

Sendou continued, keeping his gaze on the notebook, "Asajima unlocked the door from inside the side stage. No matter how many pairs of eyes monitor the stage exterior, the murderer can access the gym from backstage... but the mystery remains on how to leave with the door locked."

As stated by Sendou, half of the locked room mystery, as well as the background to Asajima's murder, began to come to light.

He intended to meet someone there. Judging from the lowered curtain, the conversation between them was likely not meant to be overheard. Consequently, he was killed.

The issue is, who is this "someone"?

The new development expanded the list of suspects to include virtually anyone without an alibi between 3:03 and 3:15. Because it means anyone could have entered the gym from backstage.

The only clear suspect exclusion among those without an alibi came from Risome's firm denial regarding Nao Sugawa.

"Damn it!"

Faced with this situation, reflecting Risome's scheme, Sendou clicked his tongue in displeasure.

When Hakata, freshly shaven, walked into the living room, he saw his sister Yuzuno sitting at the dining table, dressed in pajamas, gnawing on some bread.

"Good morning, brother!"

"Morning! Sure you woke up early. Morning training... oh, that's impossible, the gym is closed. What's wrong with you?"

"Nothing. I toasted some bread, you want some?"

"Mm..."

Usually, she slept just until she was about to be late. It was odd. He murmured to himself while sitting down.

"Are you sleepless because of yesterday's shock?"

"No, no, I just happened to wake up early."

"Well, I hope that's true... Are you going to school today?"

"Mm-hm. Oh, oahlah oh." 

"Don't talk with your mouth full!"

Yuzuno gulped down the bread and said, "I'm going to school. Just for half the day in the morning. They said there's an emergency meeting. I guess, no, it's definitely to explain the incident's situation."

"True. The students are still in the dark. That's to be expected. You going to school is a great help to the police."

"Why?"

"Because with all the students in one place, it makes it easier to question them."

Yuzuno silently continued munching her bread, then said to Hakata, "So you're coming to school today too?"

"Of course. There's a mountain of stuff to do. Handbooks leading to suspects... ah, nothing."

Hakata barely stopped himself. It was because of his unintentional disclosure that things turned problematic yesterday. In any case, discussing a murder case over breakfast with his sister was foolish.

Fortunately, Yuzuno was engrossed in her breakfast and didn't catch what he was saying. Though it stung his pride, it was just as well that she hadn't heard. Hakata downed his toast with milk, promptly got up, and said, "Don't worry about the incident anymore. Leave it to us."

"Alright."

"...?"

Her agreeable reaction stood in stark contrast to yesterday. A total turnaround.

"Um, alright... also, let that Risome person know, to keep out of the case. By the way, what's the deal with him? He just appeared out of nowhere."

"What do you mean, 'what's the deal?'"

"The student council kids said he's a detective. Is that a joke?"

"Well, kind of..."

Yuzuno thought for a moment, tilting her head before answering, "He's not really a detective, more like an anime nerd, a useless guy."

This answer caught him off guard.

"Well done, Hakata's sister."

The anime nerd, useless guy, nodded in satisfaction and said, "I didn't think you'd actually do it."

"No need to thank me."

"In reality, the success rate was pretty low, wasn't it? First, bet whether your brother would come home instead of staying at the station, and another bet on whether you could find the notebook, not to mention slipping in without getting caught. It was a terrifyingly high-risk gamble."

He remained arrogant, not making it feel like a compliment.

"I barely found the notebook. I didn't expect my brother to leave it in the suit pocket. First, I rummaged through the drawer."

"You should blame your lack of thoughtfulness. Frequently used items are best kept in a fixed location. Moreover, he came home dead tired late at night, going straight to bed. Putting the suit on a hanger, the notebook remained in his pocket."

"Why didn't you tell me if you expected all that?"

"How was I supposed to know you'd be so thoughtless?"

...Indeed, it wasn't really a compliment.

Thud, thud thud thud thud—a rhythmic knock came on the door. This seemed to be a dedicated signal, and Risome replied, "Come in." The door immediately opened, and at only eight in the morning, the school newspaper president already spoke with gusto.

"Good! Mor! Ning!"

"...You mean 'this camera'? Nobody knows it!"

"Doesn't it mean that in 'this camera'? That's Murakami's special greeting. Quick, where's that thing?"

Kaori glanced around before settling her sight on the digital camera on the short table.

"Whoa! You did it! That's amazing!"

Surrounded by Kaori's exaggerated applause, Yuzuno finally felt a sense of achievement from her efforts.

"The case notes are on there, right? Wow—so exciting! If it could all be covered in the newspaper report..."

"No, you mustn't write it! This is confidential! Resolve your excitement now!"

"Y-Yes, Kaori, if you write it, my brother will arrest me."

"Aw, I understand. But this is really great. It's like the Detective Boys or something!"

"Getting a detective's sister to be a spy, doesn't that sound like something a villain would do?"

Once again, Risome dismissed her role, yawning, "Ah—"

—Your brother's notebook should have detailed investigative notes. Take photos of the contents tonight.

That was the mission Risome had assigned to Yuzuno last night upon their farewell.

Stealing police information was a confrontation against state power, so Yuzuno was hesitant. However, to solve the case, they indeed needed the investigation's clues. Furthermore, she had already done something similar in the gym corridor, so it didn't matter much now. Reluctantly, Yuzuno accepted the mission.

She woke up at five in the morning, snuck into her brother's room, and took digital photos of every page of the notebook, successfully completing the task. Her brother, exhausted from yesterday, slept soundly, oblivious to her actions—or at least, Hakata made no mention when they met in the living room later.

Though she felt it was unfair to her brother, she knew he wouldn't heed her directly, leaving this as the only way.

"...So, where should we print these? I don't see a printer in this room."

Yuzuno observed Risome's room. Despite having two computers, a TV, and even a mini-fridge, there was no sign of a printer—or perhaps it was buried under the pile of magazines?

"I'll print at a familiar print shop. I'll handle the editing perfectly, leave it to me."

Kaori raised her hand.

"The print room, it's by the office, right? Any issues?"

"Oh, I won't get caught. I'll sneak out to print during the school assembly."

"Huh? You're not attending the assembly?"

"Why bother attending?"

Risome said, holding a ham sandwich from the fridge. It seemed he was about to have breakfast.

"Isn't the assembly about the incident? Kaori, bring them after printing. I'm off to bed."

"Got it!"

"You're really old-fashioned, you know?"

"Risome, you won't attend the assembly?"

Yuzuno was surprised. She noticed this guy lived at the school but neither attended classes nor participated in activities.

"I already know the contents, and when cases are brought up, the atmosphere on-site turns weird. I don't care to see that. Besides, I'm tired. I won't allow anyone to interfere with my sleep."

"Tired?"

"Because I didn't sleep at all last night."

Now that he mentioned it, Yuzuno noticed the dark circles under his eyes.

"Uh, you weren't up all night reasoning, were you?"

"No, I rewatched IS's OVA and DTB's second season, and then it dawned."

"...Can't you speak in Japanese?"

"It's an era of globalization now!"

With a mouth full of his breakfast—or, since he hadn't slept, a midnight snack—Risome seemed deep in thought about the case, though what exactly remained unclear to her. Yuzuno sighed and said, "Are you sure you'll be alright? If you can't crack the case, I'm not giving you that fifty thousand yen as agreed."

"Mffpmw."

"Don't talk with your mouth full... huh? You say it's fine?"

After gulping down the sandwich, Risome said, "I said it's fine. Anyway, once the assembly ends, come back here. Good night."

Finishing his midnight snack, Risome quickly snuggled into bed and began snoring beneath his blanket as Yuzuno and Kaori exited.

"He's truly a useless guy, isn't he..."

Standing by the locked door with Kaori, Yuzuno muttered to herself.

#### 2. Drama Club Twenty Hours Ago

As expected, the assembly's content was the school's briefing on the incident. Rumors had already begun spreading among the well-informed students that the old gym was the scene of a murder and Tomoki Asajima was the victim. Yet, the official announcement still triggered emotional ripples among the students, and just as Risome had predicted, the new gym took on a tense atmosphere.

The principal, with sweat beading on his broad forehead, awkwardly paused between "this" and "that" in his words, stirring impatience among the students.
After about forty minutes of briefing, an unexpected figure took the podium. It was a tall middle-aged man with sharp eyes, dressed in a suit. "I am Sendou from the Investigation Division of the Prefectural Police." The police chief took the microphone off the stand and introduced himself. The students started whispering to each other more intensely.

"The principal has already explained the situation to you. Yesterday, a tragic incident occurred in the old gymnasium at our school. From our assessment, this seems to be a murder case. We are currently conducting an investigation." A commotion broke out. "At present, we do not have enough information to arrest the culprit. Since this incident happened at school right after classes, it’s only natural that we need to understand the situation from everyone present." Another burst of commotion ensued.

"Please do not misunderstand. It’s not that we suspect any of you. We just wish to gather information to identify the perpetrator. So, later, please..." Yet another wave of commotion.

"Quiet, everyone!" — Silence ensued.

"...Therefore, I ask everyone to remain in their respective clubrooms afterward. Many were attending club activities when the crime occurred. Students returning home, please wait in the large meeting room. The investigators will meet each one in turn. During that time, please tell us everything you can remember, even if it seems trivial — honestly."

"That's all I have to say—" Sendou ended his speech and hurriedly left the podium, seemingly indifferent to the audience's reactions. The microphone was not placed back on the stand, but rather casually left on the podium.

For Yuzuno, a meeting that ended as suddenly as it began was much appreciated. Returning to the classroom would mean being flooded with questions concerning herself and Sanae, both related parties.

Sanae wanted to go to the table tennis clubroom with Yuzuno, but she feigned unease, claiming, "the thought of this case makes me uncomfortable" and pretended to head to the infirmary, while actually heading toward the cultural club activity building.

Since the police requested everyone to go simultaneously, crowds surrounded the building. To avoid trouble if seen entering the Hyakunin Isshu Literature Club room, Yuzuno hid in a secluded spot, waiting until most people dispersed, then approached the last room and knocked on the door. She gave her name, Hakata, to which Kaori opened the door.

"You're back! How was the meeting?"

"Quite thrilling! Even the detective spoke out."

"Wow, that's something. I should have checked it out. What was said?"

"More or less the usual, asking everyone to return to their respective clubrooms and wait."

Tama Risome sat cross-legged in front of a low table, gazing intently at several sheets of paper. If this were an anime program schedule, Yuzuno might have knocked it over, but luckily, it was a set of photos of her brother's notebook, enlarged by Kaori's brilliant photocopying technique. The text was clear and crisp, aiding in easy reading.

"What did the detective say that you understood so clearly! Did you deduce the investigation process?"

"Isn't there a commotion outside? Generally, cancelling all club activities is impossible. No one would come to the activity building under normal circumstances."

"Hmm, makes sense..."

"Speaking of which, your brother is quite remarkable," Risome said, tossing the stack of photos onto the low table, having finished going through all the notes.

"He meticulously recorded everything from the details of the scene to the responses in interrogations. Thanks to him, I pretty much grasp the investigation situation."

"Any new discoveries?"

"Plenty, especially interesting is the last sentence."

"The last sentence?"

Yuzuno and Kaori leaned in to look at the photos. Unaware during photographing, Yuzuno didn't notice that the photos captured a plan found in Tomoki Asajima’s student handbook. "After entering backstage, Asajima lowered the curtain and opened the right side of the stage. This proves my theory."

"Prove? Prove what?"

"Prove the motive for Asajima's murder and related matters. He planned to meet someone there, possibly the culprit. That person entered backstage through the unlocked right side of the stage. I mentioned yesterday, the girl Nao saw is not the perpetrator; this was dismissed. Perhaps that girl also left through the right side of the stage. Then the perpetrator locked the door."

"Huh? Huh?"

Yuzuno hadn't fully grasped what he was saying when Risome got up with an old-man-like groan, "Ah-yo."

"Let's go!"

"...Where are we going?"

"First to the drama club. Oh, but I need to put on my school uniform, otherwise it's a mess."

Risome, just up from bed, was still in his T-shirt and shorts. He nonchalantly changed clothes in front of the two girls, ignoring Yuzuno's attempt to avert her eyes out of modesty.

"Why are we going to the drama club?"

"To investigate their alibis. Though it's quite a hassle."

"Alibis..."

Finally, it starts to feel a bit like detective work.

"Investigating alibis. So much fun, so much fun! Ah—my blood is boiling!"

It seemed Kaori planned to tag along this time, enthusiastically clutching her self-purchased notebook with a cheerful smile.

The drama club’s activity room was on the first floor of the cultural club activity building, close to Risome's usual base of operations. To be precise, it was the third room next door.

Upon hearing a knock on the door, club head Kazuya Kajiwara opened up, expecting detectives, wide-eyed in surprise.

"Oh, it's you, Risome. What are you up to this time? Playing detective again?"

"I'm working a part-time job that pays 50,000 yen," Risome replied nonchalantly, stepping into the activity room. Yuzuno and Kaori followed, nodding and bowing in greeting, doing so for Risome as well.

This room was a bizarre space lacking any uniformity. Against the wall were backgrounds for plays; in the middle, a variety of props gathered around: a Western wardrobe, dining table, armchair, juxtaposed with tatami mats, screens, and sliding doors laid on the floor. Sci-fi-themed measuring instruments built from scrap. Three office desks with swivel chairs. Outside, on the balcony, sat a cart for transporting these items to the stage. Next to the cart, a blue tarpaulin used during yesterday's rain was drying on a clothesline.

The number of costumes was also considerable, enough to earn some rental income if activity funds were insufficient. The drama club members seemed accustomed to this setting, their attire quite eccentric.

Kajiwara wore an extremely ordinary shirt. The real issue was the other three. Aimi Sanjo dressed like a diver in a wetsuit; Shiga wore a wide-sleeved kimono with a bob-wig headpiece, and Tsubaki Matsue donned a frilly vermilion dress.

"Oh wow, my my, Kaji, Aimi, morning! And Shiga-kun and Matsue, hello!"

Extremely well-connected club president Kaori was undaunted by the atmosphere and greeted each member. The room felt more cramped as the number grew from four to seven.

"President Sana, you’re here today too?"

"Yes, I'm an excellent recorder."

“The word ‘excellent’ is unnecessary. Besides, I didn’t ask you to record.” Risome dismissively glanced at Kaori, showing her notes to everyone, and said:

"Speaking of which, your outfits are quite something. What kind of cosplay is this?"

"We're not cosplaying; we're fitting costumes. The play we're putting on is ‘Falling from the Sky Again Today,’ a comic drama about demons, future beings, and zashiki-warashi crashing into a struggling mystery novelist's home..."

"I have a few other questions."

Interrupting, Risome straightforwardly asked:

"First, two days ago, your entire group rehearsed in the old gymnasium. Then you went backstage to the broadcast room to watch the seniors' performance video. Is that correct?"

"Yes, yes, that's correct. I mentioned it yesterday, didn't I? Everyone agrees, right?" At the head's remark, the bizarrely dressed members nodded collectively.

"You only watched the one video you retrieved yesterday?"

"Yes."

"Great job!"

Unclear which part was so well done, Risome nonetheless appeared satisfied.

"Alright, next question. About twenty hours ago, after classes, first Kajiwara and this Matsue Tsubaki guy arrived at 3:03. Who’s Matsue?"

"...That's me." Tsubaki in a dress raised her hand in response. Her normally icy expression showed slight surprise, seemingly bewildered by Risome's sudden visit.

"Did you happen to meet Kajiwara and come together?"

"Yes. I usually come around this time, and yesterday, the President was early; we met in the first-floor hallway and came together."

"And the two of you stayed here until other members arrived?"

"Yes."

"Alright. You two are temporarily ruled out."

"Ruled out?"

Kajiwara repeated.

"Risome, you’re not investigating our alibis, are you?"

"Perhaps I am." Risome casually acknowledged, as if to say, "And what of it?"

"Huh?" There were whispers of discontent.

"Spare us, we didn't do it!"

"That's what I’m hoping for. Next, Keisuke Shiga."

The freckled boy Keisuke Shiga responded, "Oh, here!"

"I heard you arrived at the activity room around 3:05."

"Yes."

"That's confirmed,” Kajiwara interjected. “But it shouldn't take you five minutes to come directly from the classroom. Did you do anything else?"

"Nothing much... Just chatted with a friend in the classroom."

"Chatted with a friend."

"With about two or three people, perhaps."

"Understood, I have no further questions for you."

Risome concluded straightforwardly. At this moment, Yuzuno started to comprehend the purpose behind his questioning. Investigating alibis — Tomoki Asajima was killed between 3:03 and 3:15. Risome was looking for those unaccounted for during this timeframe.

Kajiwara and Tsubaki Matsue were in the activity room at 3:03, ruling them out. Shiga, who arrived at 3:05, lacked time to commit murder and reach the old gymnasium, and he had conversed with multiple people in the classroom, hence he was also ruled out.

"Next is Aimi Sanjo... you."

Risome turned his attention to the vice-president.

"You arrived at the activity room at 3:10. Correct?"

"...Yes."

Timidly, Aimi fiddled with the ends of her long hair, answering cautiously.

"What were you doing prior to arriving?"

"I went to the bathroom..."

"Can that be verified?"

"No, it can't... I didn't speak with anyone."

"I see, understood. Well Kajiwara."

"What?"

"Around 3:15, you moved the cart to the old gymnasium. Then, Sanjo left for the stage ahead, and you followed. Is that accurate?"

"Yeah."

"You noticed the curtain drop, then peeked from the wing toward the student athletes, conversing with Sugawa then."

"Yes... you know quite a lot!"

"Indeed. Now, an extremely important question to ask all of you."

Risome eyed Aimi and Kajiwara each before saying:

"When peeking from the wing, specifically speaking, how many seconds in length?"

"Um..." The question demanded a high degree of accuracy. After much pondering, Kajiwara said:

"Roughly ten seconds, I think."

"I see. During that time, Sanjo was beside you, and two first-year students were at the left stage entrance, right?"

"...Yes."

"Good, the questioning concludes. Thank you!"

As abruptly as it had begun, the questioning wrapped up suddenly. Risome turned away, and Yuzuno, along with Kaori who had been consistently taking notes, quickly followed suit.

As Risome was about to leave the room, Aimi Sanjo, looking like she was suspended in mid-air, called after him, "Wait!"

With a slender strand of hair entwined around her finger from nervously fiddling, she asked, "I say... am I a suspect?"

"You're more than just a suspect,"

Risome retorted, saying veiledly:

"For all we know, you might just be the culprit!"

He replied bluntly, expression indecipherable as to whether he was joking or serious. He glanced at the drama club members frozen among the stage props, then closed the door.

3 Student Council Figures
"No, no, no, no, no, this can't be!" Kaori shook her head vigorously while walking from the activity building to the main school building, nearly causing her glasses to fly off.

"Aimi is the culprit? Impossible. Aimi is a naturally innocent optimist, she couldn't kill anyone!"

"Many pretend innocence yet harbor darkness within, like Kawashima Ami from 'Toradora.'"

"Indeed. Yet..."

"Is Sanjo really the murderer?" asked Yuzuno.

"Not confirmed, but it's a consideration for now, naturally allowing for other possibilities."

Risome's response was surprisingly cautious.

"But why suspect Sanjo?"

"Because, she alone could create the conditions for a locked room."

"...Meishi?" Yuzuno repeated the term, glancing at Kaori, who appeared equally baffled.

By his account, it was as if—indeed as if the locked room mystery had been solved.

Risome declined elaborating further, proceeding toward the school building without stopping. Yuzuno and her partner entered the school building after changing shoes. It seemed he was probing the earlier mentioned "other possibilities." Yet the destination remained unclear.

"Where exactly are we going?"

"To the place most unrelated to myself."

"...?"

"Oh, I know," Kaori, more accustomed to his ways, raised her hand to answer. 

"To the student council office, yes?"

“I thought police perhaps, but it’s you,” Akihiro Masaki, the student council president, pulled a chair for the visitors, inviting them to sit.

“Risome, it’s the time when everyone’s waiting in their rooms. Aren’t you worried the police might arrest you for wandering about?”

“Unfortunately, I’m neither in a club nor part of student council.”

"Those who go home right away are in the large meeting room. Didn’t attend the assembly? You’re hopeless!" 

Contrary to his words, Masaki appeared refreshed, seemingly relishing the state of affairs. Vice president Chizuru Yatsuhashi exchanged smiles with Yuzuno, similar to the day before.

The student council office was neat and orderly. Folder binders with aggregated documents lined the bookshelf in plain view. Half-written files were systematically organized in a tri-color box on the desk corner. Pens were in a penholder, paperclips in a box. The floor was spotless. Having spent time in Risome’s room and the drama club room—both a bit avant-garde—the stark difference was notably pleasant to Yuzuno.

Though they were unexpected guests, three steaming paper cups were placed before them. The tea was served by secretary Yukiko Hibiya, who the previous day closely followed Chizuru only to be sent back. Yukiko happened to be Yuzuno's classmate too.

“A detective, right? I didn’t know we had a detective at school. Oh, how fascinating.”

Yukiko swayed her bob-cut hair with delight, making one question if the student council at Kazeoka High School was truly dependable with so many gossip enthusiasts present.

“So, what brings you here?”

The only seemingly sensible person, the treasurer Ryotaro Shiina, asked.
The young man with a shaved head, a stature so tall that no one believed he was a first-year student, and a never-wavering demeanor made people think he was a youthful soldier coming through time. In this place where all the school's top talents were gathered, Tama Risome showed not a hint of intimidation.

"I'm here to investigate the alibis of all of you."

"All of us?" Masaki responded inquiringly.

"You suspect me for being near the scene, but why investigate the entire student council? It's a bit strange. Why do that?"

"I don't know." The sharp query was flatly dismissed with a casual punch from Tama Risome. The student council president shrugged and said to the vice president beside him, "They want our alibis... What should we do?"

"What's the harm in that? It's quite amusing. Risome-kun, it'll be over soon, right?"

"I hope so." The sleepy detective lazily rose from his chair.

"Let's start with Masaki. You're from class 2-4, so you finished school early. But yesterday, instead of going to the student council office, you went to the student council's supplies room to draft documents. That was around 2:55 PM. Correct?"

"Yes, you've got it spot on. How did you find that out?"

"I don't know. After that, you heard a scream around 3:15. Then you looked into the gymnasium and found Asajima had been killed."

"That's right. You remembered everything?"

"I don't know."

Tama Risome always had a rough way of changing the subject. "I don't know" became a convenient phrase used repeatedly.

"In summary, you lack an alibi for a full twenty minutes."

"But we made a call around 3:10." Chizuru said.

"Can you make a call from a murder site?"

"If you want to, you can. There was a TV drama where a man was making a phone call while committing murder."

Masaki maintained a radiant smile and proactively cut his own lifeline short. "Anyway, I don't think my alibi holds. I spent twenty minutes preparing documents for a meeting, but they could have been prepared in advance as a disguise. From over here, you could clearly see what Nakamura was doing standing in front of the gymnasium, but she didn't notice me at all."

"You're well aware of your situation." Risome also slightly curled his lips, though the expression was far removed from Masaki's refreshing demeanor. Masaki replied, "Thank you for the compliment."

"But you can be assured! There are several reasons that considerably reduce the likelihood of you being the culprit. Though it doesn't achieve a pristine white result, it's somewhat akin to a hazy sakura pink."

"Have you been drinking? Using metaphors like that. It's normally described as gray, isn't it?"

"Hahahaha" — the two top-ranked students in the entire grade laughed heartily together, attempting to dispel this atmosphere.

Then Risome's gaze turned to the student council vice president, ranked third in the year: "And then it's you. Hmm, what's your name..."

"I'm Chizuru. Chizuru Yatsuhashi from class 2-3."

"Oh, I remembered. Yatsuhashi, where were you between 3:03 and 3:15?"

"I left the classroom right after three o'clock. What time did I get here?" Chizuru brought her fingertips close to her lips, thought briefly, and replied, "Oh, right. Almost ten past three. As soon as I entered the room, I received a call from the president. Isn't that right?" She confirmed with Yukiko, who nodded promptly in agreement.

"Ten past. After class, before you came here, what did you do?"

"I bought a drink from the vending machine in the cafeteria."

"Can anyone verify that?"

"No, I didn't meet anyone, so it can't be verified."

"Hmm—"

"…Am I suspicious too?"

"Yes, you're twice as suspicious as Masaki."

"Ri-Risome, how could you say that..." Yuzuno finally couldn't help but voice her reproach. Surprised that Chizuru, the one who had created the opportunity to rescue captain Sugawa, was being considered a suspect by Risome. She must have been shocked herself.

As she thought this, she suddenly heard Chizuru laugh lightheartedly and say, "Double. So my level of suspicion is astonishingly pink."

She's so poised! — Could it be because she's absolutely certain she's not the culprit?

"Next is the two over there… What's the name of the short one?"

"It's Yukiko Hibiya." Kaori whispered in his ear, a bit dumbfounded.

"I see. Hibiya, where were you and what were you doing after school yesterday? According to the earlier account, you were already in this room when the vice president arrived?"

"Yes. I was here around 3:04. And I've been here ever since." The diminutive Yukiko Hibiya looked at Risome with serene composure and answered.

"Until about 3:07, I was with the advisor, Higuchi-sensei, who can vouch for me."

"That's good. You've been eliminated from suspicion. The last one is you, Special Ops."

"I'm no Special Ops, I'm Ryotaro Shiina, the treasurer." The calm response came from the alleged Special Ops, the youth soldier, Shiina.

"Shiina? Student council treasurer Shiina? What a pity. Why is your name Ryotaro?"

"Why, you ask? My parents gave it to me."

"Let's move on. What did you do after school yesterday?"

"After school yesterday, I immediately went to the library. Finished returning some books and aimed to find something new to borrow, but in the end, didn't borrow anything. Then I came to the student council office after that. Hibiya-san and the vice president were already there." Shiina's expression and demeanor showed no change as he spoke in a flat tone:

"Not long after I arrived, we heard over the school broadcast that something had happened at the old gymnasium. I originally planned to head home as instructed, but since senior Masaki didn't come to the office, I was concerned, so the three of us stayed here until we understood the situation."

"When did you enter this room?"

"Around 3:20. However, I didn't meet anyone in the library, so I can't verify my whereabouts. The library committee member was in the archives, so I just placed the books I needed to return into the return box."

"Oh..."

Risome fell silent.

The student council members, four in total. One had an alibi, three did not.

Moreover, everyone had a correct and objective understanding of their situation.

"I see." Risome took a sip from his paper cup of green tea, but his eyes remained fixed on the four people in front of him, then said, "You're really a formidable group!"

"Thank you for the compliment!" The president displayed an unwavering cheerful expression.

4

Following their departure from the student council office, Risome began scratching at his bangs.

"Why do I feel like you're very anxious?"

"No, it's just that this group of student council folks is frustrating. It's irritating how they're putting on airs about not being involved."

"Isn't this what anxiety is?"

"I'm saying I'm the one who's anxious."

I couldn't understand the difference between the two.

"Masaki and Yatsuhashi, in particular, seem suspicious. I initially thought this case was a solo act, but if the two of them are together, collaboration is also possible."

"These two have a pretty good relationship. Ever since they contested for the president's position at the elections, their names have always come up together. How did it go again? An enemy today is a friend tomorrow..."

"That's incorrect. Having a good relationship doesn't mean they're accomplices, right?" Yuzuno scolded Kaori. She still believed suspecting the vice president was putting the cart before the horse. After all, she was the one who recommended Risome to investigate.

"That's not for sure, for example, Masaki’s call. It's possible Masaki didn’t say anything, and Yatsuhashi just chimed in appropriately, pretending to be him."

"There you go again... Isn't Sanjo the most suspicious one?”

Risome nodded immediately: "Yes, you're right."

"In reality, it's hard to identify Masaki as the true culprit. The perpetrator purposely left an umbrella in the bathroom to create a guise. Since the umbrella was for men, it's highly possible the real culprit is female. That's why I find Yatsuhashi suspicious. However, I don't believe she's capable of creating a locked room scenario in the gymnasium."

"Then it would be unlikely to be one of them. Why do you suspect them nonetheless?"

"Irritatingly impenetrable attitude, I guess. I just want to vent."

"Are you in elementary school?"

"What are we going to do next?" Kaori closed the notebook she'd been reviewing and asked Risome.

Indeed, this wasn’t over. There was more investigation to be done regarding the alibis... Until when? Would we be searching all the club rooms one by one until nightfall?

“Are you planning to search through every club room like this?”

Hearing Yuzuno's question, Risome shook his head and replied, “That’s not possible. Next up is the last one.”

“Hmm? The last one? I wouldn't mind if we searched them all. Only covering three seems a bit careless…”

“It's fine this way.” Risome concluded impatiently. Fine, if he said it was fine, then it was fine.

"So where exactly are we headed?"

"We can already see it. It's just over there… huh?"

As Risome pointed to indicate the direction, he suddenly came to a halt.

Opposite them was a sign for the "Broadcast Room." Of course, they were headed to the headquarters of Asajima Tomoki, the ground of the broadcasting club. It was indeed necessary to investigate here.

However, this wasn't the cause for Risome's pause.

At the time, two men emerged from the opposite corner of the corridor, arriving at the broadcast room before them and were about to enter. One of the men looked in their direction and noticed Yuzuno among them.

Just like yesterday, a lamenting voice cried out:

"Yuzuno! What... what are you doing this time?"

"Hello Detective! Long time no see! How have you been?"

"Never been worse! All because of you!"

In stark contrast to Risome's calm and collected demeanor, the police inspector was already teetering on the edge of his patience.

"I should have told you to have all the students stay in their activity rooms, waiting, right? Why are you roaming around?"

"Waiting? Ah, that's what you meant. I forgot. But our whereabouts during the incident were already clear. If there were any reports needed for you, Detective, we already mentioned it all yesterday. Can't say you need to question us more. So us wandering around shouldn’t be an issue, isn’t it?"

"That's not it. All means all."

"What bureaucratic red tape you have!"

"Shut up!"

Inspector Sendou glared at Risome. Yuzuno noticed he was holding the black umbrella she'd seen before.

"That umbrella..."

"Huh? Oh, we're trying to find the umbrella's owner."

"I think the owner won't reveal themselves, as it's something the culprit left behind. Didn't I mention it yesterday?"

"Hence, we're conducting confirmation." Inspector gritted his teeth as he spoke, then turned to Yuzuno:

"But why is Hakata's younger sister fooling around here again... and I heard you also caused trouble for the officer on guard duty yesterday..."

"I am Kaori Sakasaka from class 2-1, the head of the newspaper club." Just like when she met Yuzuno, Kaori handed over a business card, beaming.

Risome too, Kaoini too, aren’t they intimidated by the police?

"Oh, by the way, she's the one who can confirm I wasn't at the scene yesterday."

"Yes, yes, I can verify that! From the end of class till around 3:15, we were in the classroom discussing how bottom rollers use treaded sliders when armored cavalry turns, discussing with Risome. It's a kind of innovation; we had differing views due to our varying values..."

"Enough."

Sendou interrupted her, not even taking her card.

"Anyway, you three should return to where you should be, and stay there obediently. If you leave right now, I'll let you off."

"But that won't do. We need to investigate the alibis of the broadcasting station members next."

“Oh, what a coincidence. So are we.”

Feigning cluelessness with his words, the inspector was already visibly irritated.

"In that case, let’s go in together. How about it?"

"What a constructive suggestion from the Detective. Then we'll comply and gratefully accept."

"What are you saying!"

His anger finally burst through the threshold. Shiina’s brother, standing behind the inspector, flinched in fright.

“If I tell you to return, you return! That's an order!"

Yet, unfortunately, they were hardly the type to just obediently comply. A quick glance at the door of the broadcasting station, Risome said:

"I’d be happy to return after leaving here, but not before. In any case, we need to talk to the broadcasting team folks, this investigation is crucial for solving the case!"

"Of course. As it involves the victim's club, its activity... However, investigations are our job."

"And it's a job I could earn fifty thousand yen from."

"That’s of no concern to me!"

"Alas, that’s disappointing. If we understand the situation from the broadcast station, the range of suspects could narrow to around five people."

"...What?"

Sendou seemed interested in this, yet also seemed infuriated with himself for displaying such interest, screwing up his lips.

"Nonsense."

"It's true."

"...But no. Not just those involved yesterday are suspected. There might be something you aren't aware we discovered late last night."

"If you're referring to the intriguing notes in Asajima-kun's notebook, I already know."

"How do you know this?" Inspector exclaimed in surprise, leading brother Shiina to be equally startled. Yuzuno felt as though brother Shiina was silently reprimanding her with his eyes, saying: "What did you do?" She quickly averted her gaze elsewhere, pretending nothing was wrong to avoid interrogation.

“Well, the fact that I know is pretty irrelevant. Listen up, Detective, using this note as a basis, you can narrow down suspects to less than ten people. And you don't need to question everyone one-by-one like you are; just getting a segment of testimony will do."

"Bu-But… how is this so?"

"Explaining it here would take till dark. So, to let both my and the police's investigative methods function effectively, it's best if we enter the broadcast station simultaneously."

The inspector seemed somewhat swayed by Risome’s eloquence.

But, resolutely, he regained his firm stance, turning his slight smile back into a flat line: “No, there’s no proof you’re perpetually right. Besides, you asked us yesterday to check Asajima’s DVDs, claiming one had been stolen. But after the officers cross-checked everything against records, nothing was found missing, surely that's a pity."

“Oh, I see. But that’s good news.”

“Goo…what? What did you say?”

“Good news! A missing DVD with no record means it's something he didn’t want a record of. Then, he planned secretly meeting someone specific. A secret disc and a secret meet-up. See? How it all connects?”

“……”

It seemed Sendou hadn't anticipated this at all, momentarily rendered speechless.

“No, wait… But this doesn't confirm a DVD was stolen…”

“It was stolen, nearly one hundred percent certain. As for evidence, I'll explain after we investigate the broadcast room. Are we going in now?”

“Wa-Wait!” 

Sendou stopped Risome, who was about to knock on the door, turning helplessly to his subordinate for assistance:

“What should we do?”

Having unexpectedly gained the right to decide, Shiina’s brother appeared hesitant. However, when he met Yuzuno’s eyes again, he gave up resisting, sighed, and said:

“Alright, they won’t mess up the scene like yesterday; they’re just following our investigation. Let them come. And even if we drive these kids away, they'll just return, causing another mess for sure!” 

“…Indeed.”
"If that's the case, we might as well let them come with us." After some argument, Sendou finally compromised, though it wasn't a particularly proactive compromise. He gestured with his chin to Yuzuno and the others, "Follow along."

"But, don't do anything unnecessary!"

"I never do anything unnecessary; I always do meaningful things." Risome gave a reply that didn't quite sound like an answer and smiled at the detective.

The broadcasting room in the teaching building was a replica of the old gymnasium, just twice as big. Machines, machines, and more machines lined the walls. Various colored cables sprawled across the floor, and headsets were piled high on the table. However, since this broadcasting room was used every day, it was tidier than the one in the old gym. There was a partition at the back of the room, probably an office where a specialized large camera and long-handled microphone could be seen. Videotapes, DVDs, and CDs used for daytime broadcasts were neatly arranged on the shelf. There were also a few laptops, similar to those in Risome's room. Four students were seated on metal-framed chairs around the table: two girls and two boys. Everyone wore grim expressions.

"Are you members of the broadcasting station?" Once inside, Sendou showed his badge. "I am Sendou from the Kanagawa Prefectural Police Investigation Division, and this is my subordinate, Hakata. Also, there are some tagalongs... but don't mind them."

"Sakasaka? What are you doing here?" A girl with glasses and messy hair exclaimed upon seeing Kaori.

"Hello, Chinatsu!"

"You know each other?"

"Yes. She is Matada Chinatsu from class 2-4. She's my glasses buddy."

"Oh, hello... I'm Matada." She introduced herself to Sendou and the others, in a manner similar to Kaori's.

"What are you doing here? Are you here for a newspaper interview?"

"No, no, I'm accompanying Tema."

"Tema... oh, Risome-san." Only then did Chinatsu notice Risome, who was hiding behind the detective near the wall.

"So, the rumor was true..."

"Rumor?"

"Oh, nothing." She hastily dodged Sendou's frown. Yuzuno somewhat understood what she meant. Chinatsu was in class 2-4, the same year as Captain Sugawa. Perhaps the captain shared the idea of inviting Risome to solve the case with a few close classmates.

“…Alright, that's fine. Could the rest of you introduce yourselves?” Sendou quickly changed the subject, wary that Risome might continue to attract everyone's attention.

Responding to this, another girl stood up from her chair. Yuzuno was familiar with her; she also participated in the school promotional VTR they watched yesterday. She was a girl with deep blue hairband pulling back her hair, revealing her forehead.

"I am Vice Leader Morinaga Yuko, from class 3-1." She said with a clear announcer's voice, just like in the promotional video.

"You're in your third year, huh? Asajima-san is also in his third year. Aren't you planning to quit this club?"

"Yes, as per the leader's wish, we intend to continue until summer break…" Now, their leader was no longer here. The atmosphere became heavy. This time it was Sendou's turn to become flustered.

"I see, thank you. Next, what's your name?"

"Me? I'm Tsudanuma Kanzou from class 2-2." Said the tall boy sitting next to Morinaga Yuko. The name Tsudanuma sounded familiar; it seemed like Kajiwara from the drama club had mentioned it.

"…Kouhei Sugamo from class 1-6." Thus, the last member of the broadcasting station finished introducing himself. His long hair and slender eyes gave him a slightly gloomy appearance. Although he was a first-year student, Yuzuno did not know him.

After getting to know their names, Sendou took out a stack of stapled papers from his suit pocket. He glanced at the paper for a moment and then asked Morinaga Yuko:

"According to the members list, besides Asajima-san, there's another person not present. Miho Akizuki from class 2-3, where is she?"

"Oh, I heard she caught a cold and took a day off today. She didn't attend the club activity yesterday either."

"She wasn't well since yesterday?"

"No, she didn't attend the club activity yesterday without notifying me. I emailed her, but received no reply. However, today I learned from her class 3 homeroom teacher that she caught a cold. So I think she might have started feeling unwell yesterday."

"I see. Well, there's nothing that can be done about that." Though the chief inspector said this, a gleam of sharpness appeared in his eyes. Perhaps he planned to make a surprise visit to this member's home after concluding the school investigation.

Then he put the list back into his pocket and formally began questioning.

"You're all aware of yesterday's incident, right? Your leader was killed."

"We know."

"Asajima was not a problematic youth at school or home; how did he behave during club activities?"

"He performed well in our broadcasting station. Asajima was a responsible leader, mild-mannered, and his filming skills were top-notch... everyone liked him."

Said Morinaga Yuko. The other members nodded in agreement.

"I see," Sendou said, looking as if he accepted their viewpoint even though, if there were issues, they wouldn't admit them easily. Perhaps he already knew there was nothing wrong after questioning other clubs about the station’s situation and was merely reconfirming.

"Did he show any suspicious behavior before the murder? Anything at all."

"Don't know... he organized the club activities normally."

"Yesterday, Asajima went to the old gymnasium, didn’t you know?"

"No, we thought he would come at the usual time, but he never showed up. I was worried because I didn't know what was going on. That’s when teachers arrived and instructed us to broadcast to the entire school notifying something had happened at the old gym...we had no idea Asajima was involved, so we just went straight home..."

"I understand. Then, after school yesterday, where were you all, and what did you do?"

"Are you investigating our alibis?" Of course, Yuko’s expression wasn't pleasant.

"As I mentioned at the meeting, it’s merely a precaution.” "Morinaga-san, where were you?"

"Yesterday… I came here right after class ended. I planned to do a final check on the school promotional video Asajima brought."

"When you say right after, what time are you referring to?"

"Around 3:03 p.m. I met Tsudanuma in the hallway and came in with him, so he should remember too."

The chief questioned Tsudanuma if that was true, and he confirmed, saying they stayed in the broadcasting room the entire time. It was similar to the pair form of Kajiwara and Tsubaki from the drama club.

"Do you know what time the other members arrived?"

"Yes. Sugamo came after 3:15, around seventeen past. Matada arrived even later, about twenty minutes in. Then, the teachers quickly came in."

Yuko answered fluently. Only then did Yuzuno realize they might not know Asajima's precise time of death. This might also be the chief’s strategy.

"Sugamo, what were you doing before 3:15?"

"After class, I went to a nearby store to buy a sweet bun because I was a bit hungry. Then I went back to school and to the broadcasting room."

"You went to a store? What's it called?"

“‘Kasugaya,’ you find it right outside the north gate.”

“They sell bread in the school cafeteria too, why did you go outside?”

“The bread I like is sold only at that store.”

“You went even with such heavy rain?”

“…Yes.” Sugamo confirmed. His expression seemed to say: This is a fact, it can't be helped. The questioning continued. When Sugamo came to the station's activity room, he indeed had a bun, but he had already thrown away the receipt.

"I'll confirm with the store later," Sendou said as he ended the questioning. But Yuzuno thought, "Kasugaya" is a family-run store, and the elderly lady at the register seemed a bit confused last time, so it might be hard to verify.

"Lastly, Matada, you arrived at 3:20. You're from class 2-4, so your class should have finished earlier. Where were you in the 30 minutes leading up to that, and what were you doing?"

“…I went to the infirmary."

"The infirmary, why?"

"I was experiencing menstrual cramps... and wanted to lie down for a bit."

Chinatsu blushed as she added. The chief inspector, who prioritized work over considerate attitudes, apologized as he looked down slightly.

"According to our investigation yesterday, during that time, the school nurse was in the staff room."

“Yes, no one was in the room, but the door was unlocked, so I took some painkillers I had brought and lay down to rest for about twenty minutes. I felt a bit better afterward, so I came straight to the activity room.”

"So you lack an alibi for the crime scene."

"Nobody else came to the infirmary, probably..."

"I see. That's fine, this is just for reference."说道。兄弟。 As Ichirou from Kajiwara’s group was taking notes, this section was encircled. Others at the scene did not have alibis during the period of 3:03 to 3:15, a gap of twelve minutes.

“I see…”

Next, Sendou raised an umbrella with one hand and took out a bow tie from his pocket, asking:

"These two items were found backstage at the old gym. Do any of you recognize them?"

He showed them to each member in turn, but the broadcasting station members all shook their heads in denial.

“Hmm.” Sendou put the bow tie back into his pocket, shifted his gaze away from the broadcasting station members, glanced at the silently standing Risome by the wall, then moved over to the shelf holding the DVDs and tapes.

"Asajima seemed to enjoy filming a lot."

"Yes, after all, he's the broadcasting station’s leader."

"He always carried a camera with him, capturing whatever he saw."

"Yes. When we were on training excursions, he spent more time observing through the lens than looking directly with his eyes. He's that kind of person."

"Have you heard of any troubles he got into because of it?"

"…What do you mean?"

Yuko’s expression clouded over further.

"There’s some unconfirmed information suggesting a DVD Asajima had might have been stolen from the crime scene..."

"The DVD? Are you talking about the school's promotional video?"

"No, that one’s still here. We believe it should contain other content..."

仙堂表达得越来越不清楚，他再次回头恶狠狠地盯着提供这模棱两可信息的里染。里染却装作跟自己毫无关系，摆弄着架子上的透明胶。 但是就在这时，津田沼忽然嘟哝道： “没准是那个。” “啊？津田沼，你知道些什么吗？” “哦，去年不是也发生过吗？秋月同学的。”

“Ah...”

The vice-leader also seemed to recall something. Sendou quickly asked:

"What happened last year?"

“Well, um, something happened…" Yuko seemed reluctant to speak, she hesitated and lowered her head.

However, it seems she couldn't resist the pressure from the detective in front of her and soon began to speak bit by bit.

"Last September… someone in our broadcasting station, Akizuki, was bullied."

"Bullying?"

"Whether it's bullying or extortion… it seems like some girls from the same grade regularly called her out and took her money."

Sendou sighed with an "Oh dear." Yuzuno felt the same way. Even though this is a relatively peaceful high school, after all, it accommodates nearly a thousand students with various personalities and thought processes, such incidents are inevitable.

"Later, one day, she couldn't take it anymore and came to us for advice. At first, we planned to inform the teachers or the police, but Asajima said it would only be temporary. Adult interventions couldn't solve the problem. He spoke as if he had seen such things somewhere before."

“He said he encountered a similar situation in middle school, so he understood."

Added Chinatsu.

"Unfortunately, you didn't rely on us, but it's okay. What method did he use? Did he fight the bully?"

"No, Asajima wasn’t skilled at sports; even against girls, he might not have won. So, he used his weapon."

"Camera?" Risome spoke in a low voice for the first time since entering the room.

"Yes, the camera. The place where Akizuki was called to was always the same, so Asajima hid in a discreet spot and filmed the extortion scene. Then, the next day, he met the perpetrator and told her that the scene had been recorded on DVD. If she continued with such acts, he would hand the footage to the police…"

“I see. Faced with such footage, we indeed can’t just take temporary measures. If not, he would avoid being expelled from school.”

“Yes, it seems they understood that and never bullied her again.”

After finishing, Morinaga Yuko bowed her head again, feeling ashamed of disclosing this secret. This embarrassment lingered, absorbed by the soundproofing materials on the wall.

In any case, Asajima indeed had a strong execution ability. Tomoki Asajima wasn't only responsible but had a solid sense of justice. He acted decisively, using the weapons at his disposal.

But – thought Yuzuno.

Although Asajima filmed the extortion scene and recorded it on DVD, as the chief said, there are no suspicious videos found in the room. It has been nearly a year since the incident, so perhaps it has already been disposed of, or—

"The perpetrator, do you know who it is?"

Sendou sternly asked.

Although the bully's name was out there, it was still unsettling to casually disclose someone’s name, so the broadcasting station members remained quiet, almost restraining each other. But it was only a moment.

"…It’s my classmate from class 4, Nakamura."

Mentioned Matada Chinatsu.

Nakamura. The delinquent student who had been waiting for friends in the rain by the old gym. Their uniform untidy and hair dyed blonde.

“Oh, so…”

Brother said, as if he had grasped some supporting evidence.

“Brother, what’s up?”

“Well, during questioning yesterday, when Nakamura mentioned Asajima, it was as if they had known each other for a long time. I've thought it was a bit strange.”

“In fact, they were long-time acquaintances. From her perspective, Asajima was a justified opponent.”

Crossing his arms over his chest, Sendou spoke with powerful eyes, reminiscent of when he suspected Captain Sugawa, like a beast capturing its prey.

“Thank you. The information you just provided is very valuable and will greatly assist in capturing the murderer.”

“Oh, thank you…”

“We’ll be leaving now. You may also go home. I think you know without me saying, please do not disclose what has happened here to anyone…”

“Could you hold on for a moment?”

Someone called after the chief from behind. It was Risome. He finally left the wall, stepping forward a few steps. Transparent tape stuck to his fingertips.

“We still have a few questions to ask.”

“Hey, I told you not to do anything unnecessary…”

“This is necessary work.”

“….”

Compromising under the insistent pressure, perhaps due to his earlier compliance, Sendou lowered his permission criteria.

Risome scanned the entire broadcasting room from left to right and then smiled:

“It’s a nice room.”

“…Thank you.”

Yuko replied despondently.

“I wish I had this kind of equipment in my room. It’s not just the hardware but the software is complete. It’s indeed the broadcasting station. Next time, I’ll borrow some stuff from you."
"By the way, the TV seems brand new. I heard you guys just replaced it two months ago?"

"Yes, because the old one was completely worn out."

"I heard you moved the old TV and player to the old gym, right?"

"You know quite a lot."

"The head of the drama club told me."

"Oh, Kajiwara told you that. Yes, the drama club members helped us move it."

"Is that because the drama club often uses the broadcasting room?"

"Exactly."

"That makes sense."

Risome looked pleased, while the members of the broadcasting station and the detectives were puzzled by these seemingly irrelevant questions.

"Are there any other groups that frequently use the old gym's broadcasting room?"

"Uh... it’s us and the drama club, and the student council, I suppose."

"Just those?"

"Yes. The choir and wind ensemble usually perform in the new gym."

"What about the teachers? Do any teachers use that broadcasting room frequently?"

"...I think it's just us and the student council's advisor teachers."

"Is there a chance anyone else could use the old gym's broadcasting room?"

"I don't think so, because the door is always locked. The keys kept in the teacher's office should only be lent to the drama club, the student council, and us."

The vice head answered every question, and Risome nodded happily with each answer.

"Speaking of keys, Asajima has three keys to the broadcasting rooms, right? One here, one for the old gym, and one for the new gym."

"Yes, we only have a key for this room, but the head has all three."

"So, you don't have the keys to the gym's broadcasting room. That's a pity."

"Huh? Why is that?"

"Oh, it’s nothing. By the way, do you know how Asajima usually carries the keys?"

"How he carries them... I think he puts them in his pants pocket."

"Is it in the right or left pocket?"

"That I wouldn't know..."

"Oh, what a pity. But it's fine. Now, how about the DVDs? He usually keeps them in his bag, of course, but when he's outside filming or something, where does he put the discs?"

"Oh, that I remember. He puts them in the back pocket of his pants, on the right, right?" Yuko confirmed with her companions, who all nodded affirmatively, indicating that the image of the head with a corner of a disc sticking out of his back pocket had made a deep impression on them.

"He always stuffs the discs there. I asked him if it was uncomfortable, and he said he was used to it and didn’t want to change. He wouldn’t put a half-finished DVD in his bag; instead, he would fixedly place it in his pants pocket."

"I see. By the way, do you know what the DVD of the school's introduction video looks like? For example, the color on the surface?"

"I don't know. The head edited it himself and burned it onto the disc. He was supposed to show it to us yesterday..."

"It didn't happen. I see, I see."

"...Are these matters related to the case?"

"They are, indeed. They are much more closely related than the threats mentioned earlier," Risome nodded with a smile, thanking them, "Thank you very much."

Because the person he was speaking to was a third-year student, older than himself, his demeanor was more courteous than before.

"Shall we go, detectives?" He urged the officers, as if he had been in charge from the start. Although Sendo and Hakata still had more to say, they had intended to leave anyway and thus followed his lead. Yuzuno and the others also followed to the hallway.

The members of the broadcasting station were left bewildered by Sendo's direct questions and Risome's enigmatic ones.

"Oh, by the way. The school introduction video VTR, I watched it yesterday, and it was very well done, impressive." Risome left these words and shut the door. Perhaps this man was not one for flattery, and this might have been his sincere opinion.

5

The Incessantly Ringing Locked Room

"Rieko Nakamura had a conflict with Asajima."

After leaving the room, Sendo summarized the investigation results.

"The one caught red-handed with the threat was recorded on video. That DVD is a matter of life and death for her."

"You mean, she called Asajima out? Lured him to the gym, killed him, and then took the DVD and fled..."

"Yes, the motive is clear. We can settle on her," he said, pounding his left fist into his right palm, echoing down the long corridor with a snap.

"But people saw Rieko Nakamura several times entering and exiting the gym, and Masaki also saw her from the equipment room. As for whether she had the time to commit the murder..."

"Not everyone was watching her all the time. If she had about three minutes, she could have entered the gym from the right side entrance, killed Asajima, and returned."

"And how does the locked room mystery get solved?"

"That part, I don’t know..." Hakata mentioned the most vexing bottleneck, tempering the detective's excitement.

"However, she is certainly a major suspect. The fact that she was just standing there is strange by itself."

"Indeed. Since we couldn't find the threatening video among Asajima's personal belongings, it is believed to have been taken by someone."

Once again, Risome seemed to have been right. How did he conduct his investigation? He must have known the DVD was taken and came to confirm—

It was then that Hakata noticed something around him.

"Where are Risome and the others...?"

"Ah?" Sendo was jolted from his line of thought and looked around, finding Risome and his companions had vanished.

"What the... They agreed to talk after leaving the broadcasting room..."

"Hey, Hakata, there's something stuck on your back."

"Huh?" He felt Sendo's hand touch his back. With a slight "snap," something stuck with transparent tape to his clothes was torn off.

It was a page from the notebook of a reporter named Sakasaka.

"When did this get stuck there?"

"I don’t know... I didn't notice."

"Well... these guys...” The message left was like a child's prank. Even the detective couldn't help but suppress his anger and smiled wryly after reading it.

On the paper was a simple message:

"Nakamura-san is not the culprit. Please be careful! Getting too deep will make you sick!"

"Why say Nakamura isn't the culprit? There are several reasons."

At the same time, Risome, who had walked ahead toward the cultural activity building, had already begun explaining this message. Not to the two detectives, but to Yuzuno and Kaori.

"First, several people saw her standing outside the gym, and if we connect it together, her alibi is almost perfect."

Masaki saw her; Captain Sugawa saw her; Masumura saw her on his way to and from the teacher's office; Yuzuno and Sanae saw her; members of the badminton team saw her; drama club members saw her... It’s indeed hard to imagine her being somewhere else.

"But with the gym right there, a two or three-minute window could provide an opportunity, no?"

Kaori countered.

"Three minutes isn't enough for a crime. At least five to six minutes are needed."

"Why?"

"It's too troublesome to explain to you."

Risome dodged the question with a self-centered tone and continued:

"Reason two, she cannot create a locked room situation. There’s another decisive piece of evidence, but I won’t say what it is."

"No, you have to tell us."

"It's too troublesome to explain to you."

He repeated this phrase again. Yuzuno was frustrated. For someone who's a solver of mysteries to declare it's "too troublesome" to explain was quite outrageous. He should at least use more sophisticated expressions, like "the data is insufficient" or "the hint is... think about it yourself."

They arrived at the door of the Hyakunin Isshu Club. Unlocking the door, Risome stretched widely before entering. "I'm exhausted from speaking with so many people today. Three people is my max."

"There you go with that strange talk again..."

But Risome was right; there was indeed a sense of fatigue. Despite only visiting three clubs, simply standing by for an alibi investigation was mentally exhausting.

Once back in the room, the three found places to sit comfortably. Kaori took out bottled barley tea from the fridge, poured it into cups, and they gratefully drank. Though the taste was rather ordinary, the coolness revived their parched throats.

"In the end, how many suspects are there?"

"Hmm—" Risome was engrossed in gulping down the barley tea, not responding. Kaori flipped open a notebook for him and said:

"According to today's investigation, those without an alibi are Aimi from the drama club, Masaki and Yatsuhashi from the student council, Shiina, Chinatsu from the broadcasting station, Sugamo... Hmm, about six people. Plus Shiga from the drama club, a total of seven."

"Isn't there one more?"

Risome finally moved the cup away from his mouth and commented:

"That Akizuki from the broadcasting station. She hasn't participated in club activities yesterday or today."

"Oh, yeah. That makes eight people."

Risome had boasted to the detective he could narrow it down to five suspects. Although he hadn't achieved it, the range was considerably narrowed.

—Assuming the killer was indeed among those investigated today.

"Hmm. But I don't think Miho’s involved; she's a really nice person."

"Kaori, do you know Akizuki?"

"Of course; I recognize everyone in our grade."

As expected of someone destined for intelligence work as the newspaper club president.

"Miho is a petite, honest, doll-like girl."

"To be the target of threats, they must indeed be of that type."

"That's why I said she couldn't kill someone. Besides, Asajima is a benefactor to Miho. She'd help him, not kill him."

"I didn't say Akizuki is the killer, only that she doesn't have an alibi."

Risome glanced at Kaori, adding in a quiet tone.

"The killer is almost certainly Aimi Sanjo."

"Really?"

"Really?"

"For real!" Amidst the exclamations, he put the cup on the short-legged table and lay down in his fixed position on the bed.

"But you just said this was temporary, right? Other situations might still occur."

"And since no other situations occurred, it’s decided."

"Ah..."

"After gathering information at the broadcasting station, it became clear. She’s the only one meeting all the conditions. Though I don't know what conflict she had with Asajima."

"What’s the key factor? Is it the locked room?"

"Exactly."

This time, Risome had to explain as he couldn't escape with "I find it troublesome."

"Following the school's handbook memo, Asajima would have pre-unlocked the door on the right side, allowing the killer to enter from there. Though Nakamura and Sugawa were constantly at the left wing entrance and in front of the stage, no one guarded the right wing. Anyway, just leaving and locking the door creates a locked room backstage."

"Certainly."

"But the keys are kept, so they couldn't be used. That means the door had to be locked from the inside. If there were enough space for thread and needle in the door, that’d be different. However, it seems that was not the case. Even your brother, dense as he is, would figure that out."

"...Can you stop bad-mouthing my brother?"

"Alright, alright. So, it must've been locked from the inside and then accessed again. Among those who entered the gym backstage after Asajima was murdered..."

"There’s only the drama club. But still, why conclude Aimi is the killer?"

Kaori asked with irritation.

"Because she was the only one able to act unnoticed. Listen, first Sanjo Aimi entered the gym and immediately separated from the other three blocked at the left stage entrance, heading for the side stage. There was the first opportunity. When Kajiwara came to Sanjo's side, he leaned out from the side stage to chat briefly with the sports team’s Sugawa. During this period, Sanjo was unsupervised, creating a second opportunity."

"Ah..."

"Certainly, in such a short time, crossing the stage, locking the right side door, and returning is likely beyond her. However, like I mentioned, there’s this terribly primal, old, convenient, very versatile tool called thread. She could pre-tie it to the right side door handle and drag it over to the left side. There, she could inconspicuously operate it, lock the door. Pulling one of the double threads would retract both lines, which, once balled up and pocketed, would remove evidence. That’s how a locked room is created."

"..." 

Both Yuzuno and Kaori stood speechless. The unsolvable locked room mystery was unraveled so easily.

Yuzuno drank a cup of barley tea to cool her mind and reconsidered. The killer could enter and exit through the right side stage, and the door could only be locked from the inside. Sanjo Aimi had the sole opportunity to move backstage alone... explained like this, it was indeed a simple logic.

"Oh, I see now! True to form, Risome! It’s enlightening!"

Kaori, ablaze with journalistic zeal, abandoned her lenient protection of Aimi and quickly made notes.

The killer was Sanjo Aimi.

Yuzuno had only spoken to her a few times. But, as Kaori described, she was straightforward and genuine. Yuzuno liked this senior, just as she liked Captain Sugawa and Tomoki Asajima.

She was the one who killed Tomoki Asajima!

"Unbelievable."

"Think as you like, but that’s the fact."

Risome replied with a yawn, the same as that morning.

"Anyway, let's call it a day. We’ll gather around seven thirty tomorrow to verify on-site at the gym, check if any tricks played out. Kaori, prepare some thread for the experiment. If it succeeds, the case is solved."

"Isn't the old gym still locked?"

"Oh, right. Then, Hakata's little sister, bring your brother along. Just say you found the killer, and he’ll come rushing."

"Huh? Okay, I'll try."

"Thanks a lot! Alright, that’s that. I'm exhausted; I'm going to... sleep... awhile..."

The final words were unclear as he soon started snoring. He appeared truly spent.

With the room's owner lying down, what could be done? So, Yuzuno and Kaori decided to leave as well.

It seemed most students were still waiting for questioning by the detectives; the front yard was empty. Unlike yesterday, it wasn't raining today, and the breeze through the greenery was refreshing.

As they passed by the first school building, Yuzuno glanced at the entrance. There was still the noticeboard with midterm exam results behind the shoe lockers.

"Is Risome always so good at grades?"

"It’s not always like this."

Yuzuno's casual inquiry drew an unexpected answer.

"He usually hangs on the edge of the top ten, but he always holds back a bit. If he tried, getting full scores would be easy. I didn’t see him study for this test."

"So this time he was serious?"

"There’s a story behind it. You know the math teacher Okawa-sensei?"

"I’ve only heard the name. I heard he’s very strict."

"Yes, exactly, he teaches us Math II. As Tenma kept dozing off excessively in class, the teacher finally couldn't stand it. One day, he erupted and angrily declared that if Tenma didn’t score full marks, he wouldn’t get credits."

"...So he got full marks?"

"Not just in math, full marks in all subjects, as if to deliberately provoke the teacher. After the results came out, he said, 'Now I can sleep in peace.'"
"...I shouldn't have asked this question," Yuzuno regretted.

"But, it seems he himself didn't want to score so well."

"You make it sound like he was unwilling..."

"He doesn't like attracting attention."

"Is it because he's modest?"

"He's gloomy by nature. Plus, if he draws attention, wouldn't it get exposed that he's living in the activity room?"

...I really shouldn't have asked.

"Why is he living in such a place?"

"For various reasons."

It was the exact same answer she got when she asked him directly. What exactly are these 'various reasons'?

As she walked down the slope from the main entrance, Yuzuno turned back to gaze at the activity room building. Although the building itself was out of sight, she could easily imagine the useless guy who snores inside the room at the very edge.

A man who is hard to figure out. All he does is sleep, offers no explanations, has peculiar and amusing hobbies, and lives in the activity room. Is it really reliable to leave this task to him?

"Reliable."

Just as she began to feel uneasy, Kaori seemed to read her thoughts and said this.

"Tama is a useless guy, but he's smart, like a wise fool."

"A wise fool, is that good or bad?"

"...Don't worry about the details, don't worry. Anyway, despite his appearance, Tama never says anything wrong, which is very reliable. I've known him for ten years, I guarantee it."

Being described as a useless guy by someone you've known for ten years is problematic in itself. But Yuzuno thought back to yesterday:

"Yeah, reliable, reliable."

Risome, who grasped the entire situation just by looking at a shoe. Starting with an umbrella, she skillfully proved the captain's innocence. 

Today was the same. She easily solved the trick to the locked room. The news that Aimi Sanjo was the culprit was shocking, but it was something that could be fully trusted.

Whether he's useful or not, his logic is of absolute value.

"I was overthinking."

Yuzuno said with a smile.

When she parted ways with Kaori at the train station ticket gate, her worries had already shifted to how she would gather the 150,000 yen prize money.

The next day.

8:30 AM.

Backstage, on the left side stage.

Yuzuno, Kaori, and Yusaku Hakata, who they had forcibly dragged along to open the door, watched Tama Risome. Under their gaze, Risome muttered in despair:

"No way?"

A reference to the abbreviation of Shueisha's serialized manga "This is the Police Station in Front of Kameari Park in Katsushika Ward". An animated series by TV Tokyo created in 1983, "Armored Trooper Votoms".
### Chapter 4 The End Reveals All Clues

1. Changing Situations

"Oh my, brother, you don't look so good," said Risome upon seeing Yusaku, who had been dragged over by his sister Yuzuno, at the entrance of Kaze Hill High School, an hour earlier at 7:30 AM.

"I'm worried," replied Yusaku, indeed looking unwell. It seemed he had worked very late at the investigation headquarters and returned home only by morning. He was planning to take a bath and go to bed when Yuzuno persistently dragged him here.

"The investigation hasn't made much progress, right?"

"It's more like taking one step forward and two steps back... By the way, have you really solved the mystery of the locked room? Do you really know who the murderer is?"

"Of course." Risome nodded confidently. At that moment, he was quite self-assured.

"I'm about to conduct a small experiment, and if it proves the trick of the locked room is feasible, the problem will be solved."

"Well, I wish you success. If you get it wrong, you'll get another earful from Officer Sendou."

"Don't worry, I'm sure the experiment will be successful! Let's go." With that, Risome took the lead and headed down the corridor.

Yuzuno glanced at the assortment of lines Kaori had prepared—kite string, plastic string, twine mixed with wool, fishing line, and wire, all well-prepared.

"Since I didn't know which one the culprit used, I bought one of everything from the home center."

"You're very thorough."

"Gathering things is my specialty," the club president said proudly, adjusting her glasses.

Along the way, they went to the teacher's office to borrow a key. There were still very few teachers who had arrived at school. Yuzuno looked around and saw Teacher Masumura coming out from the door leading to the print room. Since he was also involved in the matter, she thought he might be amenable and asked him for the key at the right moment.

"You want to borrow the gymnasium key? Well, it's still sealed off, and entry is not permitted…"

"You see, the police have agreed to let us in, please."

"Well, if that's the case..."

With the help of her brother, they overcame the obstacle and were now fully equipped.

"Let's get a move on! I need to finish this quickly and go back to sleep." said Risome, who was still suffering from lack of sleep, urging the detective.

"Didn't you sleep either?"

"No."

"Wow, it seems life is hard even for a high school detective. Spent the whole night reasoning?"

"No, I was up all night reading 'The SS of the Forbidden Index' online, and suddenly it was morning."

"Huh?"

"Brother, you don't have to question every word he says; it's bad for your health," Yuzuno intervened just in time.

"Oh yeah, brother, were you looking for the umbrella's owner yesterday? Did you find them?"

"...No, we confirmed with all the faculty and students, including those absent due to illness, but we couldn't find them," muttered Yusaku, looking as if he was about to doze off again.

"We neither found the owner nor collected any witness testimony about someone using this umbrella."

"Exactly, at first glance it's just a black umbrella. Even if someone saw it being used, they'd probably have no impression. Have you shown it to the janitor, who seems knowledgeable about items left at school?"

"We showed it to her, and she said she had no recollection."

"In that case, it seems the umbrella must have been planted there by the murderer."

"As much as I'd hate to admit it, that's the reality."

Amid such low-blood-pressure discussions, they hurriedly traversed the corridor familiar to the members of the table tennis team.

"Ah!" Yuzuno and the others exclaimed as the door to the student council supply room opened right in front of them.

The lovely Yamato Nadeshiko and a boyish young man with rosy cheeks emerged—it was Chizuru Yatsuhashi and Ryotaro Shiina, each carrying a corrugated cardboard box full of documents.

"Good morning! You're here early," greeted Chizuru elegantly. Risome grunted an indifferent "Oh" in response, counting it as a reply.

"You have business in the gymnasium?"

"A field exercise for the locked-room trick."

"Wow, impressive. Does this mean the case is nearing its resolution?"

"It's right on the horizon."

"Do you know who the culprit is?"

"I do."

"That's great to hear."

Hearing the culprit—easily imaginable as a student among them—was identified, Shiina's expression tensed up while Chizuru remained composed, as if she was convinced Risome would certainly find out who the culprit was.

"Yatsuhashi-san, are you working on student council duties?" asked Yuzuno.

"Yes. We wanted to organize things to save time when preparing documents because it gets dusty, so we thought we'd tidy up early in the morning. You see, otherwise, we can't open the windows when it rains."

"Huh? Is it going to rain today?"

"Yes, the sky's clouded over."

Chizuru said this, glancing inside the supply room. The room contained equally elegant desks and file racks like the student council office, but mostly it was filled with tables and chairs of various sizes, brooms, coarse-threaded gloves, textbooks, spare gym shoes, plastic umbrellas, and numerous cardboard boxes. Through the interior window, one could see the gymnasium and the sky.

The sky was indeed overcast. She had been focused on pulling her brother over today and hadn't checked the weather forecast.

"It seems rain will come by noon, so we're doing a big cleanup early," explained Chizuru.

"Specifically waking up so early, that's really commendable!" Risome remarked as if the matter didn't concern him. Chizuru laughed softly and said:

"Aren't you working hard too? Going to the gymnasium so early to uncover the locked-room trick."

With that, she paused and, through her moist pupils, looked toward the old gymnasium from the supply room.

"...But isn't it quite intriguing, orchestrating a locked-room murder in a place like that?"

"Huh?" Yuzuno was puzzled by the extraordinary expression and asked again.

"If we were to name it, would 'Gymnasium Murder' be fitting? Haha, it's almost like a joke."

The vice president left this strange line with a smile, prompting Shiina to carry the cardboard boxes towards the first teaching building.

Risome's eyes followed her, echoing the sentiment in Yuzuno's mind: 

"What's so funny about that?"

Gymnasium murder.

How absurd.

The old gymnasium of Kanagawa Prefectural Kaze Hill High School. The oddities, madness, grotesqueness, and bizarre elements that could add a sinister highlight to a murder were completely absent here, in this place known as the gymnasium. There was no special layout or decoration; in fact, it was to the extreme of simplicity.

Even if a case occurred in such a place, it couldn't constitute a mysterious 'murder.' At present, the secret of this case is in the process of being completely revealed.

—Or at least, it should have been.

"—No way?" Risome murmured again to himself.

In the fifty minutes after entering the gymnasium, Risome, attempting to lock the door on the right stage from the left stage, used all the string Kaori had prepared, trying every conceivable method.

He looped the string around the door latch, pulled it; wrapped it around the back of the podium, altering the direction to apply force; even threaded it through gaps in the stage curtain to manipulate the door handle using the stage hoist.

However, all attempts ended in failure.

Ultimately, the gymnasium was simply too large. From the door on the right stage to the left stage, across the intervening stage, was more than ten meters. Extending a string such a long distance and skillfully pulling to turn the door handle was something impossible regardless of the amount of time spent. The force wouldn't transmit effectively, compounded by the fact that the old lock was quite stiff, making it difficult to turn without a direct manual operation.

The identity of the culprit remained beyond grasp.

The stage for the murder—the gymnasium—thus unveiled its fangs towards the detective.

"How should I describe this...You really surprise me!" exclaimed Risome's brother, inspecting the Hundred Poems Research Club room in astonishment.

"You actually live here? What about your family? Does the school allow this? And what are these posters about?"

They really were siblings; just like Yuzuno, he fired off questions one after another. But the room's resident wasn't answering. He lay motionless on the bed, unclear whether awake or asleep.

Risome had nonchalantly allowed the detective into what should have been his top-secret room. This alone was indicative of how significant the blow he had suffered was.

In the main school building, the bell rang. This indicated that the first class of the day was about to begin, just like any other day. But Yuzuno and the others remained in Risome's room rather than going to class.

"What's going on..." Kaori pondered aloud with confusion while preparing instant coffee for everyone.

"I thought we had it right. You see, Tama wasn't wrong at all. The door on the right stage can only be locked from the inside, something only Aimi could do."

"But in reality, it's impossible..."

"So, that eliminates Aimi as someone who could create a locked room. But if that's the case, there's no one left who could do it... Hmm."

"I'm done."

Risome, still face down in his pillow, mumbled as if he were already awake. 

"It's no good, completely no good, I'm done for, might as well die."

"Wh-what are you saying? Hang in there! If even your mind fails, Risome-kun truly becomes a useless person!"

"Ah, I really want to die. I wish the Loli Group would take turns slapping me to death..."

Yuzuno and Kaori exchanged glances.

There are many tragic ways to die, but this one was incredibly 'useless,' and he'd hit rock bottom.

"But such things happen often, no need to be so down."

"It's amazing you even figured out one trick. Neither Officer Sendou nor I could come up with anything."

"It's unfortunate that what I figured out wasn’t the correct answer; the investigation is at a standstill."

"But as I said..."

His brother sighed and said:

"Our investigation is similarly at a deadlock."

"Right, you mentioned you're currently taking one step forward and two steps back."

"Exactly... Let me vent a little." 

He swirled his coffee cup wearily and spoke slowly:

"Yesterday, after leaving the broadcasting room, Officer Sendou and I immediately went to see Rieko Nakamura to ask her about the threats."

"Huh? Didn't Tama advise against suspicion? Yet you still suspect her?"

"Of course, she had a plausible motive. And even if we don't suspect her, confirmation of testimony is necessary. Since she's a student who goes straight home after school, we called her out to a large conference room in a personal capacity. Then, she admitted to the threats and agreed that Asajima had stopped her. However, she asserted she did not kill anyone."

"See, I told you that from the start."

"But, Kaori-san, perpetrators generally deny their crimes..."

"Naturally, Officer Sendou initially suspected she was lying. But then came up the problematic DVD. With sharp eyes, Officer Sendou asked, ‘The DVD capturing the threat scene wasn’t found near Asajima, did you steal and hide it?’ And then Rieko admitted..."

"She didn’t admit, did she?"

"She admitted it. She nodded straightforwardly, saying: ‘It’s with me, at my place.’”

Yuzuno and Kaori almost spat out their drinks: 

"Ad-admitted? So the DVD is with Nakamura-san?"

"Yes. However, she said it wasn't something she took by force, but rather given to her. When we understood the situation, here's what happened: 

"After her threatening activities were stopped by Asajima, Rieko suddenly realized how foolish her actions had been. Asajima, using his skills to protect his juniors, and herself, extorting her classmates for money seemed shameful. She was unwilling to continue threatening others due to this. In summary, she reformed.

"One day, she called out Asajima and Akizuki, returned the money, and shared her thoughts with them, acknowledging her wrongdoing and promising not to engage in such behavior again. The next day, Asajima brought the DVD and handed it to Rieko, saying—'Since you have shown sincerity, let me demonstrate mine as well. This DVD has no other backups, do with it as you please, even if you want to dispose of it.'"

"Wow, just like that, he gave away something he captured with so much effort? He’s truly an honest person..."

"It seems so false that it doesn’t look false the other way round..." 

"That’s exactly it. Officer Sendou also had his doubts, but we sent someone to search her house, and sure enough, we found the DVD. If it had been otherwise, it would be easy to believe she'd stolen it and then lied deliberately. However, the DVD was found on a bookshelf covered with a thick layer of dust, indicating it hadn’t been disturbed for at least several months."

"So what she said was true."

"Yes. Her reformation seems genuine, and the fact she hadn’t discarded the DVD stands as proof. She’s far more sincere than she appears... Admittedly, this doesn't entirely rule her out as a suspect, but at least it nullifies the motive."

Yusaku drank the remaining coffee in his cup like he was downing a drink.

“Then, was she really waiting for a friend outside the gymnasium?”

Yuzuno suddenly thought of this and asked.

“Strictly speaking, no. She began secretly dating a first-year student named Saotome Yasutalo, and to keep their relationship clandestine from other students, they arranged to meet where fewer people would gather, at the gymnasium.”

“Fewer people? There were actually quite a few passerby, including us.”

“Since she doesn’t participate in club activities, she believed not many would frequent the old gymnasium. At any rate, we verified with her boyfriend; they did indeed agree to meet there.”

Secret arrangements with a boyfriend. Once the details were clarified, it became a pure reason fitting in line with a high school student.

“Thus, Rieko Nakamura is no longer a suspect. Many students still lack alibis, but none are particularly suspicious. Other than the gray area surrounding Teacher Masumura, all teachers and staff have alibis; no new witness testimony has emerged...the investigation remains just as blank as it began.”

The worth of Yusaku and his supervisor's day-long efforts seemed to be zero. Unsurprisingly, it caused him to sigh heavily.

Once finished, he turned to the still-prone Risome and said:

"This culprit is tough to crack, committing murder in a school gymnasium and yet no clues emerge as we get closer to the core. Therefore, Risome-kun, don’t be discouraged; apply yourself once more. At least regarding the locked room, Officer Sendou and I are at a loss..."

"What about Sugamo's alibi?"

"Huh?"

"Sugamo, the one who claimed to have bought bread at a store behind the school, causing him to be late to the club room. Did you verify?"

"This... well..." Yusaku, puzzled by the sudden question, answered as Yuzuno had suspected.

"The owner of 'Kasugaya' was a bit dazed and said he couldn’t remember."

"I see, thank you."

"Sugamo-kun isn't an issue, is he?"

"No, I just wanted to confirm."

"Oh, right... Speaking of the broadcasting station, there is also the suspicious Akizuki-san, isn't there?"

"Akizuki-san?"

Yuzuno frowned. Miho Akizuki indeed didn't attend club activities and lacked an alibi, but Asajima had been very kind to her. If Rieko Nakamura had the greatest motive, Akizuki as the victim should be at the other extreme.

"After understanding the situation at the school, we went to her home. Her catching a cold and taking a leave of absence was true; her mother confirmed that she had indeed fallen ill upon returning home yesterday. However, she wasn't incoherent, so we requested to see her... But she insisted she knew nothing and refused."
"We didn't get to see her in person. We asked her about the bowtie and umbrella through the access control system, and she insisted she 'didn't know.'"

"Oh?"

If it were oneself, in the situation where a senpai from the club was killed, even with a cold, even if knowing nothing, one would certainly want to talk to the police to understand the case. Is it because of the "small stature, honest" personality that Kaori mentioned that she had such an attitude, or—

"Ah, it's raining," Kaori suddenly said to herself.

Looking at the window, indeed a few drops of water hung on it. Soon, fine rain began to flow through the scene outside, quietly bringing the sound of rain. Although not as heavy as yesterday's downpour, this light drizzle seemed like it would continue for a while before clearing.

"What's going on? It's raining way earlier than the forecast."

"It's really troublesome, I didn't bring an umbrella... Brother, can I ride with you home?"

"What silly talk is this? I'm going back to the station now, but if you didn't bring an umbrella, why not borrow one from someone?"

"Huh? How could I..."

"Umbrella."

Their conversation was interrupted abruptly by Risome blurting out this word.

"Umbrella... rain..."

"Risome, what's wrong?"

"Umbrella... rain... umbrella..."

"...Risome?"

"Ahhhhhhh!"

As the scream sounded, Risome quickly lifted his head from the pillow and leaped up. His eyes were wide open, his double eyelids stretched to the limit.

"Ri-Risome, are you okay?"

"I'm an idiot."

"Huh?"

"Umbrella! The umbrella!"

"The umbrella? The umbrella you mentioned, could it be the one left in the men's restroom..."

Before his brother could finish speaking, his pocket started vibrating with the sound of a phone call. He took it out and glanced at it; it seemed to be a call.

"Oh, it's from Officer Sendou, let me take this."

He hurriedly opened the door and went out. Meanwhile, Risome continued rambling incoherently:

"Umbrella! Umbrella! Umbrella, umbrella, umbrella! I'm a fool! A big fool! As foolish as the second daughter of the Nanami family! Competing with the tofu brains of East Boulevard. I got it wrong! The illusion! Ah—oh my god! Ah—oh my god!"

"Te-Tama, calm down! What's gotten into you?"

He scratched his head while frantically spinning around the room, his childhood friend barely managing to catch him by the shoulders to stop him. Risome was still gasping for air, but at least he stopped shouting.

"What did you discover?"

"It's not that I discovered something, but I realized something incredible!"

"Wha-what is it?"

"Wait! Let me organize my thoughts."

Risome spread his palms, motioning Kaori to wait a moment, then lowered his head and started muttering again.

Then, after a moment, he raised his head as if suddenly enlightened, once again showing a wild look in his eyes.

He bounced to the window, opened it without caring about the rain splashing into the room, and stuck his head out, shouting in a high-pitched voice:

"So that's it!"

"What's going on here?"

"A locked room!"

"A locked room?"

"Yes. How could I have realized it only now? Such a simple thing! No, wait, I haven't confirmed it yet, there are some things I need to check, for instance, if there are two umbrellas, wouldn't that be too conspicuous? It's unlikely, can't rule out other possibilities, in any case, need to investigate..."

"Ka-Kaori-kun—"

Yuzuno, feeling unable to control the situation, quickly sought help from Kaori. Kaori tried to soothe him, attempting to calm him down again. However, just then, her brother returned to the room excitedly, adding to the chaos.

"No, it's bad, Risome!"

"Yeah, it's bad, brother! We've all been blind, and we all need to wear glasses! We need to wear extra-large glasses like Ansei Himegami!"

"Huh? No, I don't get what you mean, but listen to me first!"

Hakata shouted, not intimidated at all by Risome's rambling.

"A witness has been found! He says that after school that day, he saw Miho Akizuki coming out of the right-side gate of the old gymnasium."

2 Saotome's Secret Report

As soon as the unmarked police car reached the front yard of Kazenooka High School, Sendou dashed out of the car and rushed towards the staff entrance. Shirato, who was in the driver's seat, quickly followed behind.

The name of the witness was Yasuto Saotome, a first-year student in class (1).

Sendou remembered him well. He was the boy Rieko Nakamura recently started dating.

During questioning yesterday, he said he was waiting for someone there but wasn't aware of the case... Apparently, he recalled something this morning. It was said that right after the morning meeting ended, he ran straight to the teachers' office, asking the teacher to call the police.

—He saw Miho Akizuki coming out of the old gymnasium.

This was the concise witness statement he provided over the phone.

From what was understood, Miho Akizuki had no conflict with Asajima. Her staying home due to a cold was also true. However, she left the crime scene without explaining the situation and reason, which was worth noting. This was the highest level of focus since the investigation began.

On the investigation line in the chief's mind, Miho Akizuki gradually emerged as a dark horse, following Nao Sugawa and Rieko Nakamura.

The staff led them to the career guidance room where Nao Sugawa was interrogated two days ago. This was not a place with good memories, a sense of foreboding flashed through their minds.

Upon opening the door, there were already four people inside. Facing the chief sat Yasuto Saotome, whom he intended to see, and for some reason, Rieko Nakamura was also present. Sitting with their backs to him—

"Hakata?"

"Ah, Officer Sendou, you've worked hard!"

"Why are you here so early? I thought you'd be late coming from your home."

"No, I came to school early in the morning, so..."

"Early in the morning? Why?"

As soon as he looked at the person sitting next to his subordinate, he immediately understood the reason.

"…Why is it you again?"

"Good morning! Detective."

Risome, lounging on the sofa with his legs crossed, casually raised one hand.

"Let me guess what you want to say, is it 'get out'?"

"Since you know, hurry up and do it!"

"I can't do that, the last step to solving the problem is still needed."

"…Solving the problem? The case?"

"Of course."

"After hearing him out, the truth will be right in front of us."

"Ridiculous!"

"Quite unexpected. I'm not a coward who chatters while emptying a bowl of spicy cabbage in the university cafeteria, you know!"

"Huh?"

"Um, Officer Sendou, if I may."

Hakata cautiously replied:

"I don't think we'd lose anything by letting him stay. He seems to have discovered something important. You see, he wasn't wrong yesterday, was he? He said Nakamura wasn't the culprit, and it indeed turned out to be true."

"But…"

"I don't think it makes any difference."

Shirato agreed from behind Sendou.

Since both partners said so face to face, Sendou had to compromise. There was no point in arguing further, so he reluctantly nodded and said, "Fine."

"Do as you please, but as with yesterday, you're not allowed to say anything extra."

"Understood. Please have a seat!"

Risome intentionally offered the seat politely. Once Sendou sat down, struggling with a strong urge to smoke, he switched his mental channel.

"…Saotome, it's been a day since we last met."

He looked at the boy in front of him and heard him timidly replying, "Yeah."

With childlike eyes, a small stature, and rosy cheeks like an apple, he appeared neat, like a girl—honest, giving off the impression of an innocent, so-called herbivore boy. It was hard to believe he was Rieko Nakamura's boyfriend. This thought had occurred to him yesterday as well. However, the two seemed quite affectionate, sitting shoulder to shoulder, hand in hand, as if encouraging each other. Perhaps her delinquent image was just an appearance?

"I heard you have something to tell us?"

"Yes."

"You said yesterday you knew nothing... Did you suddenly remember something today?"

"No, actually, I remembered it yesterday too, but it was kind of hard to say... Then, I consulted with Nakamura today morning, and she said it's better to tell you."

I see, so that's why she came along. Typically, it would be the boyfriend encouraging the girlfriend, right? Perhaps they complemented each other well in personality.

"Never mind about yesterday. Now, what did you see? Can you start from the beginning?"

"Okay..."

One word at a time, the witness began to recount:

"The day before yesterday, I was planning to go home with Rieko, so I waited for her at the old gym. But a classmate asked me to walk with him. His house is close to the school, so I thought I could go with him first, part ways, and then come back."

He said yesterday that he accepted a friend's invitation, didn't meet Rieko as agreed, and went straight home. It seems that was a lie.

"You need to be so secretive about your relationship with Rieko?"

"If my parents find out, they'd nag..."

Saotome's face grew redder and redder. Sendou wanted to laugh, but there was no time for small talk now.

"What happened then?"

"After saying goodbye to my friend, I intended to return to school. However, entering through the main or north gate, if I encountered someone I knew, they would find it strange. So, I decided to go through the back entrance since it's particularly close to the old gym."

This date was quite troublesome indeed. But just then, Saotome showed a hint of timidity:

"However, while walking along the fence towards the back gate from the main entrance... I saw a female student coming out of the old gym."

"From which door did she come out?"

"Um, from the stage door on the opposite side of the school building... How should I put it?"

"The entrance to the right stage? The side without the restroom."

"Yes, that door."

"Do you know who it was?"

"Yes... I know."

Saotome tightly held the hand of his lover beside him and squeezed out a sentence:

"It was Akizuki from the second-year broadcasting station."

"Are you sure?"

"Absolutely. I'm in the wind ensemble. We asked Akizuki to help with some backstage work at the last concert, so I'm familiar with her."

"I see, then..."

"Do you remember the exact time at that moment?"

Sendou was about to elaborate on Miho Akizuki's appearance but was preempted by Risome.

"Hey, don't ask questions so casually..."

"They'll have to ask eventually. So, Yasuto Saotome, around what time was it?"

"Um... Sorry, I'm not so sure about the exact time... It might have been around 3:15."

"What else did you see? For instance, did you see the drama club heading towards the old gym?"

"Yes, I did."

It seemed spot-on. Saotome nodded deeply.

"After Akizuki came out, I walked towards the back entrance and saw the drama club through the fence. They were pulling a two-wheeled cart. I remember thinking how tough it was for them in the rain."

"So, they arrived at the gym at fifteen minutes, a bit earlier, around fourteen minutes. Thank you!"

"You're welcome…"

"Ahem. So, what happened after that?"

Sendou exaggeratedly cleared his throat. Saotome was obviously confused by the questions from a non-police individual, so his attention needed to be brought back.

"What was Akizuki like at that time? Was there anything strange?"

"Her entire demeanor was suspicious. The strangest part was that she didn't have an umbrella. No, it's not that she didn't have an umbrella, she didn't bring any umbrella, her hands were empty. Her actions were also strange."

"What do you mean?"

"She suddenly ran out of the gymnasium... Then turned back to pound on the door. She knocked on the door two or three times. After that, she leaned against the door, as if to catch her breath."

Sendou glanced at his subordinate, and they lightly nodded to each other. The pounding sound must be the drum-like noise that Nao Sugawa and others mentioned. It was not a drum but rather the sound of a heavy metal door. Masumura said the sound was "heard around fifteen minutes," but it was probably before that, slightly before fifteen minutes.

"Then, she stayed like that for about five seconds, then suddenly ran, opened the back gate, and ran in the opposite direction from me. I didn't see anything after that."

"She wasn't using an umbrella while running?"

"No, she got drenched."

"Hmm. That is odd... Did you notice anything else?"

"Well, it seemed she still wore her indoor shoes... And she wasn't wearing a bowtie—the one on her uniform."

Saotome said, pointing to his own chest.

"A bowtie, I see."

Another mystery solved. The bowtie dropped at the right stage was likely Miho Akizuki's.

"Is that all you saw?"

"Yes."

"What did you do afterward?"

"I went in through the back gate to the old gymnasium..."

"Did you see any footprints?"

Risome immediately questioned.

"From your memory of the indoor shoes and bowtie, your observation skills are quite strong. Did you notice footprints on the ground when entering through the back gate? Only that area has bare soil, it's easy to leave footprints."

"Footprints?"

Saotome's youthful face showed a thoughtful expression for a moment, then quickly relaxed with an "ah."

"I remember because the ground was slippery from the rain, so I was careful of my footing."

"Perfect. Were there any footprints by the back gate?"

"Before I went in, there was only one set of footprints."

"Only one set. Were there messy footprints, such as ones washed away by rainwater?"

"None at all, the rest was quite clean."

"Your girlfriend being here is really fortunate, otherwise I'd probably hug you now!"

Risome said delightedly. Saotome bashfully replied, "Th-Thank you," while Rieko standing beside showed an awkward expression.

Sendou once again—this time obviously more artificially—cleared his throat and returned to the topic.

"You entered the school through the back gate, then what happened at the gym?"

"Uh, uh. At the gym, Rieko wasn't there. The boys from the badminton club were running to the teaching building with terrified expressions, paired with Akizuki's state, it gave me the impression something might have happened..."

"Did you go straight home after that?"

"Yes... I'm sorry, I got scared suddenly."

"No, no, it's alright. Thanks for telling us this."

In summary, Saotome arrived at the old gymnasium just when Masumura had brought in Rieko and Masaki, rather than when two boys from the badminton club went to the building for help.

Masumura thought he had gathered all the students aware of the case, yet he overlooked just one: Saotome. However, as Saotome didn't look inside the gymnasium, it was understandable that Masumura hadn't noticed him.

"Thank you very much. This information is very helpful."

Upon hearing Sendou's thanks, Saotome looked down and said:

"Yeah... Is Akizuki really suspicious?"

"Hm? Yeah."

Leaving the murder scene, pounding on the door, catching her breath, then fleeing. Soaked in the rain and refusing to see the police yesterday.

If this isn't suspicious, then what is?

"But it's not certain that she's the culprit, yet she is indeed suspicious."

A rather cautious assessment.

"I see... But, I don't think Akizuki has anything to do with the case."

"Why?"

"Akizuki is a very gentle and nice person, and she got along well with the broadcasting station head... She wouldn't do such a thing..."

Saotome began stammering at this point.

Now, at least, there is an answer to why he couldn't testify about his sighting yesterday.

He trusts Miho Akizuki. Thus, he didn't want her to be suspected.
Despite how suspicious the actions he witnessed might have seemed, he couldn’t overturn the “good person” image he held of his senior in his heart. Truly, it was the same with Hakata’s sister; that’s why they say such naive high school students…

“Anyone can pretend to be a good person.”

However, the cruel line that even Sendou found hard to articulate came out of Risome’s mouth, who was also a high school student.

When he turned back, Risome was leaning casually against the wall, playing with his phone.

“If you really trusted Miho Akizuki, you should have explained the situation earlier. If you had, maybe the case would have been solved yesterday.”

“…I’m sorry.”

“It’s fine. Now, you should go back, as classes are in session. Since you’re a high school student, go back and attend class well!”

While saying this, Risome opened the door to the career counseling office, seemingly disregarding where he had left his status. You’re not supposed to let eyewitnesses leave willy-nilly!—Sendou almost shouted, but on second thought, since he had asked everything he needed, he remained silent.

The couple left the room with tense expressions, Saotome bowed respectfully and said, “We beg your leave.” Rieko Nakamura just nodded stiffly.

As soon as the door closed, Risome snapped his folding phone shut with a smack.

“Detective, we should immediately call Nao Sugawa to take a look at Akizuki’s photo. I suspect the girl she saw was Miho.”

“I am already aware of that.”

Hearing that Miho Akizuki had left empty-handed, a tension string in Sendou’s mind tightened. The girl Nao Sugawa saw entering the backstage likely didn’t have anything with her either.

“Furthermore, since Miho Akizuki ran away empty-handed, it suggests her things are still at the school. Please search her class.”

“Didn’t I say I know? Officer Shirato, would you mind going?”

Alright, alright, the senior inspector responded, leaving the room.

“Hakata, quickly gather some help to understand the situation. Since she left from the back door without an umbrella, someone must have seen her. It doesn’t matter if classes are in session.”

Sendou didn’t want to keep being outpaced by Risome, so he promptly gave instructions. Hakata, taking note of his commanding presence, hurried to action. However, Risome called to him, “Brother,” saying:

“Before understanding the situation, I have one more request for you, a very, very important one.”

“…What is it?”

“Please review the security footage from the main and north gates on the day of the incident to confirm whether any student left with over two umbrellas, then call and give the results to your sister.”

“…?”

Sendou and Hakata exchanged puzzled looks. A student carrying more than two umbrellas? Why confirm this?

“Right, didn’t you say you discovered something crucial? Exactly what did you…”

What clue did you find?—Just as he shifted his gaze from his subordinate, who was about to ask, Sendou was at a loss.

Like the previous day, Risome had disappeared from the room after saying what he wanted. By noon, the investigation was going smoothly. Nao Sugawa took one look at Miho Akizuki’s photo and immediately confirmed the girl she had seen was indeed her.

“Oh, so it was Akizuki… No wonder she seemed familiar.”

Shirato searched Miho’s class, the second-year group (3), and quickly found her belongings. In her locker was a solitary nylon backpack, seemingly waiting for its owner. Her umbrella, with dots and her initials, was in the umbrella stand at the classroom entrance.

Moreover, several witness statements were collected by police going classroom to classroom, interrupting classes to ask if anyone had seen a girl running in the rain without an umbrella, resulting in multiple witnesses. One even insisted that it was Miho Akizuki.

This fully corroborated Yasuto Saotome's secret report.

On that day, at about 3:08 PM, Miho Akizuki from the broadcasting station entered the old gymnasium from the corridor, passed right under Nao Sugawa’s eyes, and disappeared backstage. About six minutes later, she emerged from the right side stage door, and after some suspicious actions, left in the rain without an umbrella, almost as if fleeing.

Then, around the same time, Asashima was murdered backstage.

The case was cracked, without a doubt this time.

Sendou was convinced.

Even though the mystery of the locked room was yet to be solved, her actions surely related to some criminal method. Reflecting now, Risome also mentioned two days ago that the girl Nao Sugawa saw was suspicious. His deductions proved correct once more…

Although it was frustrating, capturing the culprit was paramount.

An unmarked police car sped through the drizzly rain.

On the road, Sendou remained silent, and Hakata, in the driver’s seat, also didn’t speak. Each time they stopped at a red light, the subordinate would wearily rub his eyes. He had reviewed the footage as Risome requested and messaged his sister with the results. Though it wasn’t necessary to fulfill his every wish, the man was just that rigid, which was his one flaw.

The destination—Miho Akizuki’s home, was on the ground floor of an apartment in the neighboring town. They parked in the visitor’s lot, its pavement adorned with fairy-tale-like tile art that stood out vividly. Once parked, they headed to the apartment.

After pressing the intercom and announcing themselves, her mother opened the door immediately. She likely never imagined her daughter would be a suspect, right?

“May we see Miho Akizuki? There are some matters we’d like to inquire about.”

“Ah, well…”

“I’m aware she isn’t feeling well, but we’d like to meet her no matter what, forgive us for the intrusion.”

“Ah, just a moment! She….”

Sendou was already inside. Guided by the mother's slightly puzzled gaze, he roughly deduced where the girl’s room was. Upon entering, the first door on the right had no lock and opened immediately.

His guess was correct; this must be Miho Akizuki’s room. Stuffed toys with a girlish air surrounded the bed, and a tray with medicine, water, and a thermometer stood beside it.

But…

“Huh?”

Miho herself wasn’t there.

“Excuse me, your daughter… did she go to the restroom?”

“No, she went out.”

“Huh?”

“About thirty minutes ago. She seemed to receive a call from a friend, rushed out, and I tried to stop her due to the rain and her cold not being better, but…”

“……”

Comprehension hadn’t caught up.

She left? Isn’t she still ill? Faking sickness? No, how could the timing be so precise?

“…Your daughter went out? Where to?”

“That I don’t know either. She said almost nothing before leaving, usually she wouldn’t do that.”

Even the mother seemed bewildered, but the detectives were already in chaos. Wordlessly, they stood there, blankly staring at the bed with no occupant beneath its covers.

The investigation progressed smoothly.

Until noon.

Simultaneously, the bell signaling the start of lunchtime rang on the Wind Hill High School campus.

Students shook and joined tables together, beginning to set out bento lunches. The topic on everyone's lips was consistent, all about the police that had arrived hours earlier and their inquiries.

“A girl dashing through the rain without an umbrella, huh?”

Sanae said while stuffing cabbage and pork rolls into her mouth.

“I wonder if she has something to do with the case?”

“Hmm—who knows?”

Yuzuno muttered vaguely. Though Akizuki could be the person the police were looking for, she couldn't let it slip. Besides, she hadn't personally heard the firsthand witness Saotome’s testimony.

“Yuzuno, who do you actually think is suspicious?”

“Oh, dear, I don't know…”

Though she might have confidently answered Aimi Sanjo yesterday.

“I think it's student Nakamura. I heard she’s done bad things before.”

“Really? I thought she seemed pretty nice.”

“Why?”

“Well, um…”

Because she's changed, no longer bullying others, and even got a boyfriend in the first year—that had to stay unsaid.

Being surrounded by this kind of conversation was already unbearable, yet as she had been on the scene during the incident, curious gazes from those around her only intensified the pressure.

Yuzuno took her phone from under the table to check it.

She'd received a text message during the fourth period class, from her brother. She wondered what it could be and opened it to find short text:

“Please tell Risome they couldn't find a student like that.”

…A student like that, what kind of student?

“I’m heading to the nurse’s office,” Yuzuno said.

“What? Are you not feeling well? Is that why you were late this morning? I’ll come with you.”

“Oh, that’s not necessary. I'll be fine on my own. Thanks!”

Though feeling sorry for Sanae, Yuzuno managed to slip away. She hastily left the classroom and ran towards the cultural club activity building.

On one hand, she needed to relay the message to Risome. On the other, she wanted to know what exactly the witness statement about Miho Akizuki entailed. Moreover, she was unsettled by Risome’s frantic state this morning. Could it be that he had cracked the mystery of the locked room? He repeatedly shouted “umbrella!” Could it be related to umbrellas?

She dashed through the rainy mist towards the shell that had once been the Hyakunin Isshu study club.

Upon a few knocks, Kaori opened the door for her, as usual.

“Oh, Yuzuno~.”

“Hi, Kaori, have you been here?”

“No, I went out for a bit.”

“Out? Not for class?”

“I have a major task.”

“Ah, Hakata’s sister. Your brother contacted you?”

Risome’s voice came from inside.

“He texted saying: ‘There wasn’t such a student,’ what student?”

“A student passing through the gates carrying two umbrellas.”

“…?”

Even with Risome's response, she still couldn't grasp it. As she entered the room, puzzled—

Yuzuno froze.

She noticed something that didn’t belong amidst the lively noise exactly like in the morning, a new addition. Rather than say an unfamiliar object, it was another person.

Sitting on the opposite side of the short-legged table was a girl draped in a blanket over her shoulders. Her layered short hair matched her petite frame perfectly.

The girl was curled up, sipping a steaming cocoa, showing slight fear upon seeing Yuzuno suddenly enter. With her round eyes, a pretty and docile, almost doll-like face with a feverish blush on her forehead. The clothes peeking from under her blanket were casual, not a uniform.

To call her an anime character’s figurine, she was too large, and as a poster, too three-dimensional. Here stood a real-life beauty.

“Who is this…?”

“Let me introduce you.” Risome, as usual, lying in bed, said indifferently. “This is Miho Akizuki from the broadcasting club.”

“Hi.” She greeted politely.

**3 The Story You Don’t Know**

“Akizuki, why are you here?”

“I invited her here.”

When Yuzuno asked, Risome straightforwardly replied.

“No, to be exact, I had Kaori call out Akizuki and bring her here.”

“That’s not what I mean, it’s why…”

“The police are after Miho, you see.”

“Oh, I see… what?”

Yuzuno was nearly swayed by Kaori’s simple explanation. But no amount of explanation could easily sway her.

“The police are looking for Miho as a suspect?”

“If the police seek someone, it’s generally for such a reason, right?”

“If so, that’s terrible! We’re harboring a suspect…”

“Hey.”

The one at the heart of the matter raised her delicate arm.

“I… am not the killer. I didn’t do anything.”

“…Is that so?”

“It’s exactly that.”

“That part, I know!”

Risome rose from the bed, sitting across the table facing Miho.

“I know you’re not the culprit. Even if the police don’t, I’m certain. The moment I heard Saotome’s testimony, I was sure.”

“So, you rescued me from the police?”

“Rather than rescue, it was more like an interception.”

“What?”

“Because I have loads to ask you. It’d be troublesome if the police got to you first.”

“What do you want to ask…?”

Yuzuno finally got the gist.

According to Risome, Miho—though for reasons unknown—wasn’t the killer. But at the same time, she did indeed leave the murder scene. Why would someone who isn’t the killer be at the murder scene? Behind this bizarre act, there should be corresponding circumstances and reasons.

What Risome sought was information. The story Miho experienced within the case, only she could know.

“Therefore, though I’m sorry for requesting this while your cold still bothers you, I need you to recount the situation back then. Why were you at the murder scene and why did you flee from there?”

“This matter…”

Miho clutched the blanket tightly, lowering her head. After waiting a while, she showed no sign of speaking up.

It seemed she was scared of something.

“Don’t worry about it.”

Risome quickly said.

“Even if you reveal everything here, nothing you fear will happen. The killer won’t have a chance to target you before the police teach them a lesson. I guarantee that.”

“But I…”

“You want the one who murdered Asashima to be caught, right?”

“……”

“So do I.”

He added quietly.

Risome’s eyes met Miho’s on the same level, unwavering. His eyes, usually appearing drowsy, were now bright and focused, the black pupils unerringly locked on Miho.

Yuzuno thought, so he does wear that expression too. Although she wasn’t being watched, she felt as though she’d be drawn into those deep black eyes. Those cold eyes were aimed not to intimidate Miho, but the killer in the path of her testimony.

Miho continued gripping the blanket tightly, hesitating for some time. However, noticing Risome waiting for an answer and the encouraging eyes of Yuzuno and Kaori, she seemed to make up her mind, sighed slightly, and gently—indeed, gently—nodded.

Then, she haltingly began recounting the entire story.

* 

She received a call from Tomoki Asajima, exactly one week ago, on the night of June 22.

“In fact, earlier this month, I caught a student doing something bad.”

After quickly exchanging pleasantries, he cut to the main topic straightaway, his tone serious.

“I informed the person about it, and they came to consult with me, saying they’d never do bad things again, asking me to return the video to them. Therefore, I plan to hand over the DVD next Wednesday after school at the old gymnasium.”

“Old gymnasium? Why there?”

“For fairness, you see. The other party isn’t an easy one to deal with, and meeting in a deserted place might lead to unexpected situations. But think about it; if it’s the old gym’s stage, we can draw the curtain to keep others from seeing, and if anything happens, I can call for help or step out from behind the curtain, immediately attracting attention. Isn’t that right? Especially with Sugawa from the table tennis team, who goes to the gym early every day, I can feel at ease.”

“Oh, that makes sense… well, and then?”

“Even with the countermeasures I mentioned, I was still a bit worried. So, I wanted to ask if Akizuki-chan could be present at the handover scene as well.”

“Me, to the scene?”

“Not exactly to the scene, you could just hide nearby. Can’t you make it?”

“No, not that. If the station head needs my help…”

“I plan to meet the person one-on-one at 3:10 in the afternoon on Wednesday. I will lower the curtain in advance and unlock the door on the right-side stage. He will enter from there to avoid being seen. So could you be at the backstage too, hiding quietly, just in case, and call for help if anything happens?”
"Help?" 
"The person in question is far more dangerous than Rieko. To protect himself, he might do anything. I'm not entirely sure, but I have a gut feeling. So, I want to be extremely cautious." 

Tomoki's voice was heavy, and I could sense his genuine wariness toward the other person. 

"Okay, but I’m not sure how much I can help with my limited ability..." 

"I know, but you're the only one who can help me with this, Miho. The other members of the broadcasting station don't know that I've given the footage to you regarding Rieko's case." 

"Ah, right... I understand. I’ll go. It's 3:10 PM on Wednesday, right?" 

"Yes. Don't worry, it won't harm you. If something happens, just run and find someone. Don’t force yourself, just do what you can, alright?" 

"Okay..." 

"Thanks! Goodbye," Tomoki said, then hung up the phone. Miho was taken aback by this sudden request and stared blankly at the phone. 

The head of the station had uncovered another misdeed without her knowledge. Then, just like what happened in her situation, he asked the other party to apologize and handed over the footage as evidence... 

No, it was somewhat different from her situation. This time, the head seemed overly cautious. Had he not found definite proof that the other party had repented? What kind of person was involved? What wrongdoing was captured on film? 

Miho couldn't shake her worry, but ultimately Tomoki didn’t reveal the full truth to her. 

June 27th, 3:05 PM. 

As Miho waited in the classroom, she headed towards the old gymnasium. 

She left her belongings and umbrella in the classroom. Although Tomoki had sounded so serious, nothing should happen, right? She should be back soon; it wasn't something she particularly needed to bring a bag for. 

She walked through the corridor towards the old gym. 

She saw Rieko Nakamura standing in the rain with an umbrella. Although Rieko had apologized for the blackmail and returned the money, Miho still feared her. So, she hurried across the corridor. Fortunately, Rieko didn't seem to notice her. 

Upon entering the gym, Nao Sugawa of the table tennis team was diligently doing stretching exercises on her own. True to being the "master" of the old gym like her senior said, she was always there. If anything happened, she could call out to her. Miho jogged past her, entering the stage area from the right-side door. 

In the dim light, she checked her watch. It was 3:08 PM, just on time. The curtain was drawn, so Tomoki should be there. 

She observed the stage through the gap in the side curtain but saw no one. What was going on? Perplexed, she walked towards the center of the stage and saw feet sticking out from the side of a lectern. Then—

"What?" 

She was completely frozen. 

Tomoki Asajima was already dead. 

Why was he dead? Tomoki, the head of the station, why? What happened? A knife, blood, so much blood. Did someone stab him? Murder? Who on earth...

She suddenly came to her senses. 

In front of her was Tomoki's body. He was leaning against the lectern, his expression calm, eyes closed, motionless. His slightly tilted left side was drenched in red blood. 

She felt awful, but not like she wanted to vomit. She stood there in blank silence, utterly immobile. 

Perhaps it was the table tennis team members. She heard cheerful voices of girls chatting from the other side of the curtain. It was only a few meters away, yet it felt like the sound was coming from a distant horizon. 

At this moment. 

She heard a "clank" sound. 

It was faint, but unmistakable. Not outside the curtain, but on this side—in fact, it was coming from the direction of the left-side stage. 

Clank, clank, clank... 

Someone was coming down from the second floor. Coming down the iron stairs from the broadcasting room on the left-side stage, deliberately lightening their footsteps. 

Who was it? 

It must be the murderer. 

The moment she realized this, Miho's feet began to move towards the right-side stage, the opposite direction. For some reason, it never occurred to her that she could go outside the curtain. Her first instinct was to flee directly in the opposite direction of the murderer. 

She ducked into the curtain on the right-side stage and saw a pool of blood on the floor. She almost fainted but instinctively avoided it. 

She leaped, taking two steps at a time up the stairs, hiding in the shadows, catching her breath, and started observing the stage. However, due to the drawn curtain, she couldn't see the stage's situation. Still, she could deduce the murderer's movements from the footsteps and other sounds. He seemed to have walked from the left-side stage to the center of the stage near the lectern, pausing slightly. She heard the sound of clothing rustling. It seemed he hadn't noticed her presence yet. 

What should I do? 

She asked herself, clutching her sweaty hands tightly. 

In any case, I have to escape first. 

If I run into the murderer, he'll kill me. Didn't Tomoki also say that? If something happens, run out immediately and get help. Isn't the current situation exactly "something happening"? Quickly run from the entrance to Sugawa and the others, then seek their help. It's simple, and I'll be saved that way. 

Yet, she still didn't move. 

It wasn't that she was paralyzed with fear but because a question was stirring in her mind. 

If I run now—won't the murderer also get away? 

Leave the backstage and get help. Sugawa and the others might be thrown into confusion, unable to grasp the situation immediately. Then, the murderer would realize something was wrong. By the time they checked inside the curtain, the murderer would have already left through the right-side stage door. Then, perhaps they'd never catch him throughout their lives. 

I alone cannot escape. 

So, what should I do? Stick my head out and call Sugawa and the others? Then, if the murderer tries to flee past me, I stand up and stop him... No, that's too scary, I'm not that brave. 

In that case, the only thing I can do— 

Someone seemed to be moving on stage, footsteps approaching this way. The murderer, having finished everything, was trying to exit via the door he came in, leaving through this exit that led outside behind her. 

In a near-mad panic, Miho looked around and suddenly noticed a poster for the cultural festival laid flat under the stairs, likely left by the cultural festival committee after some meeting. 

A black long umbrella was laid on the poster. Next to it was a bulging plastic bag, seemingly containing a pair of sports shoes. 

There could be no one else who put an umbrella and shoes in a place like this, they must belong to the murderer. 

What followed was almost instinctive for Miho. She took off her ribbon tie from her chest and conspicuously threw it on the umbrella's handle. Then, she unlocked the door and slipped out. 

The murderer entered the side stage, and she gently closed the door at almost the same moment. 

In the open external space, Miho took a deep breath, let the raindrops hit her, and silently prayed. 

The murderer intending to retrieve his belongings would, of course, notice the ribbon. He would also realize that the door, which was locked when he entered, was now unlocked. Then, he’d realize that someone other than himself was here and become too cautious to exit through this door. There's Rieko Nakamura on the left-side stage, and outside are Nao Sugawa and others, making it impossible for him to escape. Please, God, let it be like this— 

However, God did not hear her prayer. 

In the next moment, the door handle turned. 

The murderer chose confirmation over caution. Who put the ribbon on the umbrella? Was that person just outside the door? The individual seemed to want to understand the situation. 

Miho's confusion reached its peak. The murderer might come out now, facing off with her. Will he kill me? Or is he just trying to escape? 

No, he killed Tomoki. He'll probably kill me too—

Killed Tomoki—

Bang! Bang!

Realizing this, Miho banged on the iron door desperately as a substitute for shouting: You’re not allowed through! 

Not allowed to come out from here! I won't let you escape!

And then she heard a click. 

On the other side of the door, someone locked it. 

"...Hoo... Hoo..." 

Miho leaned against the door, regulating her breathing. 

After waiting a few seconds, she didn't perceive any change. The murderer might have given up on exiting this way. He was now trapped with no escape, a rat in a cage behind the stage... Theoretically, that should be the case. 

"Great..." 

She muttered softly. But at that moment, the fear came rushing back. 

Did the murderer not see me for real? Won't he still try to escape from here? 

Might he be on the other side of the door, glaring at me even now...?

The image of Tomoki's murdered body flashed in her mind, and Miho couldn't take it anymore. 

In a panic, she dashed away from the door and ran toward the back exit right in front of her without looking back. Without an umbrella, her clothes were soaked, she wore indoor shoes, and she didn’t have her belongings, but she couldn’t care less. 

She ran and ran until she reached the station, finally noticing the looks from people around her. Her rain-soaked blouse clung to her, showing the outline of her undergarments. Since she had money in her pocket, she bought an umbrella and shoes at the supermarket and tossed her indoor shoes in the trash bin. 

Her wet body started to feel cold, and she developed a high fever as soon as she got home. She was never in the best of health, to begin with. 

She caught a cold.

*

"I see." 

Tama unfolded his arms after listening to the explanation. 

"So, you really did encounter the murderer. No, you didn't meet him directly; rather, you both sensed each other's presence. That's why you can't tell the police." 

"Yes. I'm scared because the murderer might take revenge on me if I testify..." 

Miho looked down at her now mostly empty cup; the hot cocoa was no longer steaming. 

"I'm sorry, if I had been braver, things wouldn't have..." 

"No, no, you did quite well. After your account, many things are now confirmed." 

"But... But," she said with a frown, "if I had stopped the murderer right there and saw what he looked like, or if I hadn’t run away after going outside...we could have caught the murderer immediately." 

"No, that’s not true..." 

"That’s right!" Before Yuzuno could refute, Miho said decisively, "The murderer hasn’t been caught, right? He must have escaped through the right-side stage door after I left. It was because I was cowardly that the murderer got away..." 

"But wasn't the right-side stage door locked?" Kaori, cleverly refilling the hot cocoa, remarked. 

"Huh?" 

"Yes, it was a closed-room scenario. All exits were locked, so how the murderer disappeared remains unknown. It’s not Miho’s fault..." 

"A—A closed room? What is this?" Miho shouted. Perhaps due to police restrictions, the media hadn’t reported the case. She hadn't been to school because of her leave, nor had she talked to the police, so naturally, she didn’t know about it. 

"Yes, that's what..." 

"It’s fine, since we’ve come this far already," Yuzuno's explanation attempt was interrupted, this time by Tama. 

He tapped the edge of the low table, seemingly contemplating something. 

"You can't run. Hmm, indeed, that's a famous line. You can't run. Hmm, what a lesson." 

As he muttered to himself, engrossed in understanding, he stood up. 

"Miho, I have three questions to confirm with you. First, when you were observing the murderer from the right-side stage. You mentioned hearing the sound of clothing rustling; did you also hear any plastic rustling?" 

"...No, I didn’t hear it." Miho answered, her expression saying: Why this question? 

"Second, the shoes placed with the umbrella. What kind of shoes were they? Please answer as best as you can from memory." 

"They were ordinary, somewhat worn, off-white sneakers... Sorry, I can't remember much else. They didn’t really stick out from the bag." 

"What about the umbrella? You put your ribbon on it, so you must have looked closely." 

"Yes, it was a rather large umbrella that seemed quite expensive... Oh, right. There was a faint brand logo imprinted on the umbrella fabric." 

"No damage on the umbrella?" 

"None, it looked almost new... Oh, but there might have been a bit of a scratch on the umbrella handle. About two centimeters long." 

Tama seemed quite satisfied with her answers and nodded several times in agreement and then moved next to the table. He disregarded the increasingly cluttered room and rummaged through the pile of comics. 

“Miho, you did well, just like Tomoki. Neither of you confronted head-on, but did what was within your power, fighting the enemy in your unique way.” 

"But, but in the end, I didn’t do anything that could force the murderer..." 

"Didn't do anything? Nonsense! Quite the opposite!" 

He exclaimed while retrieving something from the manga pile. 

It was a stack of photos Yuzuno had taken the day before—a copy of her brother's notebook. 

“If you had run away swiftly from there, the murderer might have never been caught. But you didn’t run. You resisted a little. And that became the key point. Your action forced the fool who killed Tomoki into a corner.” 

"I... I don't understand what you mean, sir..." 

But Tama didn't answer Miho's query; he silently flipped through the photographs and soon stopped at one. 

"Yes, just as I thought. Exactly so." 

"What is it? Tama?" 

"What did you find?" 

Kaori and Yuzuno asked eagerly. 

Tama turned around calmly, without making incoherent sounds like earlier that morning.

"Yuzuno, do you have your brother's phone number?" 

"I do." 

“Now, they're probably in a frenzy because they can’t find Miho. Call him and quickly bring him back. Then, tell him to gather all the relevant people.”

“Okay… By relevant people, you mean?”

The recluse shut-in otaku, combined with a useless detective, said calmly:

“I know who the murderer is.”
Intermission—A Challenge to the Reader

In modern society, even if a detective novel includes a "challenge to the reader" section, it's rare to find those peculiar readers who would take up the challenge, re-read the summary of the problems, and guess who the culprit is or what the crime method was. Therefore, adding such a section is just a waste of paper and time; it's downright foolish. However, this is just the author's personal opinion. It's possible that there exist idle minds far beyond our imagination that are extremely keen on such challenges, and I believe it would be foolish to underestimate this brilliant, gentlemanly invention. Hence, I've included a "challenge to the reader" in keeping with tradition.

As everyone can tell from the title of Chapter Four, all the materials needed to solve the puzzle are fully in place at this point in time. There's no need for readers to get excited and speculate, "Perhaps the clue is hidden in this casual dialogue" or "This seemingly irrelevant scene might be a foreshadowing," and so on. All clues are clearly recorded in the text from the beginning of Chapter One to the end of Chapter Four. There's no need for leaps of logic. If readers analyze the clues one by one and think systematically, they can naturally deduce the answer.

The author challenges readers to find the truth before that useless person living at school does—namely, the name of the murderer of Tomoki Asajima and the truth behind the locked room mystery—because it's quite possible for you to achieve this.

Finally, to make the puzzle-solving process fairer, I have outlined three notes here:

① Detective Hakata's investigation notes are extremely detailed, documenting everything from the dialogue in interviews to the conditions at the scene. In other words, you can assume that by the day after the incident, Tama Risome already knew everything Detective Hakata had learned up to that point.

② At the start of Chapter Four, Risome had already noticed the relationship between the umbrella and the locked room, but as he himself stated, at that time, he merely grasped an opportunity to form a hypothesis. He became convinced of the truth after hearing Miho Akizuki's testimony.

③ Tama Risome's deductions are all based on objective facts. Therefore, I don't recommend you seek the culprit from the angle of motive.

With that, I wish you all great success.