Saihara, Amami, and Akamatsu began investigating to find the true culprit who killed K, but the investigation quickly slammed into a dead end.
Most of the students involved in the sleeping-pill bread operation had alibis.
First was Momota, the one who had spearheaded the plan.
"So... you're saying you came up with the idea, but you didn't handle the preparations yourself?"
"Yeah... I was supposed to handle the charge! Don't forget, I'm the [Ultimate Astronaut], y'know?"
"Um... what does being an astronaut have to do with charging in...?"
"Besides, if I remember right, Momota-san got subdued by Harukawa-san and tied up within seconds of rushing in..."
"S-shut up!! That was just a mistake!!"
Since he had an alibi that placed him only in the idea stage and the frontal assault, he was excluded from the list of prime suspects.
"I-I only committed the crime of making the [Universal Master Key]...!"
"Is that really all?"
"S-Shirogane will prove I stayed in my lab the whole time..."
"T-that's right... Master, no... Iruma-san was only doing research..."
"...That's all well and good, but since it's Shirogane-san's testimony, I can't exactly say it inspires confidence."
"K-Kiibo!! Kiibo was getting maintenance too!! Please believe meee..."
Iruma, who remained under suspicion for quite a while, was eventually cleared thanks to Kiibo's testimony and his recording function.
"This part's all clogged up... doesn't it feel awful...? It's okay now... I'm gonna pull it out for you..."
"H-hhhnnnngh!!"
"T-this is a misunderstanding!! Iruma-san was only performing maintenance on my body...!"
"Th-that... a robot and a human... biologically... um... anyway, they can't exactly do... that..."
"That's not what it was at aaaall!!!"
Let us all agree to forget the minor incident in which, thanks to Kiibo fumbling the controls, an absurdly embarrassing recording of breathy moans got played back instead.
"Gonta was standing by with Chabashira-san in case something happened... Gonta is stupid, so that's all he could do..."
"But if both of you were there, how did Momota get taken down that easily?"
"Because that idiotic male charged in the instant the door opened! If we'd all gone in together, we might've had a chance!!"
Gonta and Chabashira, who had also participated in the operation, were likewise pushed further from suspicion once it became clear they had only joined right before the plan was carried out.
And so Saihara, Amami, and Akamatsu finally turned their scrutiny toward the last remaining suspicious person: someone who had participated in the plan and had no alibi.
"Nngah...! I'm really not the culprit! All I did was crush up the sleeping pills, mix them into the bread, and hand it to Momota!"
"That's exactly the problem, Yumeno-san..."
They were talking about Yumeno, who tearfully insisted that if she'd really wanted to kill K, she wouldn't have done something underhanded like poison him. She would've killed him with flashy magic instead.
"Yumeno-san, where exactly did you find the sleeping pills? Are there even sleeping pills in this school?"
"I-I found them with a search spell..."
"......."
"A-actually, last night I was given a heavy mission, so I searched the storage room for ages, but I couldn't find anything useful for the plan... so I used my summoning magic..."
"...Yumeno-san."
"N-ngah..."
"...I grumbled that if there were sleeping pills, common sense says they'd be left somewhere easy to find, like on the dining table."
"And then...?"
"After that... I kept looking for a long time... then I went to the dining hall to take a short break... and found a bottle of sleeping pills just sitting there on the table..."
"What...?"
"You can't seriously be saying you used something that suspicious without questioning it... right?"
"........"
When Yumeno started sweating bullets at that line of questioning, Akamatsu slowly opened her mouth, her face stiff with dawning horror.
"If that's true... then the only person who could qualify as the culprit is Yumeno-san, isn't it?"
"I-I'm being framed here!!"
"Huh? That's a lie, isn't it?"
"Nngah! Oma, since when were you here...? No, wait, more importantly, why are you saying that too?!"
"Nishishi... good question. Why am I, I wonder?"
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The trio had uncovered one crucial fact—that Yumeno had mixed a suspicious drug into the bread—but after that, the investigation made no further progress.
"Y-you saw a suspicious bottle like that, and you still didn't tell anyone?"
"G-Gonta is sorry... Gonta is... stupid..."
"Well... because I thought it'd be more fun that way?"
That was because Gonta and Oma admitted they had also briefly seen the bottle sitting in the dining hall, which shattered even the theory that Yumeno was the hidden mastermind behind it all.
"S-see that!! I didn't do anything wrong..."
"Yumeno-san, if that's what you think, should we tell Mukuro-san the truth?"
"...Spare me."
"Nishishi... then sure! I'll go tattle right now!"
"W-wait! Oma, wait just a moment!"
"Well... if you join the anti-student council faction, maybe there's a chance I'll be lenient?"
The three stared blankly at Yumeno as she went pale and immediately started begging Oma. Then, with a collective sigh, they began reasoning through the person behind the incident—the one who had placed the bottle on the table.
Because whoever had done something so purposeless and opaque had a very high chance of being the Mastermind of the killing game.
"Could it be... Hoshi-kun is the Mastermind?"
After a long silence of thought, Saihara finally voiced his suspicion that Hoshi might be the one behind the incident.
His reasoning was this: Hoshi had been passing by the lab at the exact moment Momota opened the door to ask for help, and Oma had already floated the theory that Hoshi was the Mastermind, so wasn't the possibility fairly high?
But that speculation was rendered useless almost immediately, because too many students had seen Hoshi in his room for practically the entire day yesterday.
"I... think we need to take another close look at Shirogane Tsumugi-san."
After that, Amami proposed another theory: that Shirogane Tsumugi, the [Ultimate Cosplayer], might have used her talent to construct some kind of trick.
"Pyahahat! Is that so? Hey, you! Cosplay me right now!"
"B-but...!"
"Move it already, will ya!?"
"U-ugggghhh!! O-okay, I will!!"
"Watch closely! This would've been a waste for me to enjoy alone... perfect timing!!"
But the moment Iruma heard that, she gleefully announced she'd show them something interesting and ordered Shirogane—who had somehow become her pet completely—to cosplay as her. The theory of Shirogane as culprit was demolished almost at once.
"Py-pyahahat! You guys... sneaking off where no one can see and having threesomes all the time... I know all about it... hnghiiiiiit!!"
"Hey!! When did I tell you to copy my way of talking too?!"
"S-sorrrryyy..."
"Shirogane-san... what on earth are those hives all over your body...?"
"I-I... when I cosplay a real person... I break out in hives all over..."
"...In that case, a trick using cosplay is impossible."
That was because the instant Shirogane cosplayed Iruma, angry red welts erupted all over her body.
Eventually, Akamatsu proposed a theory that Gonta, Momota, and Yumeno had acted as accomplices together, but it was so implausible it was dismissed almost immediately.
"...In the end, we're right back where we started."
"...Yeah. Whoever did this prepared everything unbelievably well. Maybe... we won't be able to uncover them through normal means."
"That's right... this case is twisted way too badly. Even when it comes to the culprit for the Class Trial itself... we can't tell whether the culprit is the person who set out the drug, Yumeno-san who mixed it into the bread, or Harukawa-san who ultimately gave that bread to K-kun."
"What exactly... was the true culprit aiming for?"
The students began debating with the information they had gathered so far, but no decisive answer emerged. Time alone kept slipping away.
"Hmm... if this keeps up, we'll never reach the end. For now, how about we look into the most important thing at the moment—the [Book of the Dead]?"
"...I guess we don't have much choice."
"Good idea, Amami-kun."
After discussing it for quite a while longer, the three decided to follow Amami's suggestion: check on how the [Book of the Dead] plan was progressing, then discuss what to do next.
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"Shuichi? Kaede? Rantaro? Hi~! Did you come to join the student council~?"
"N-no... we just came to see how the [Book of the Dead] plan is going..."
"Kukuku... more guests...? How delightful..."
"...Huh? Shinguji-kun? Why are you here?"
"You still didn't know~? This is Korekiyo, the newest member of our student council~! Give him a warm round of applause~!"
The three stepped into Angie's research lab, the gathering place where the student council was preparing the [Book of the Dead] ritual, and were stunned to discover that Shinguji had become a member of the student council.
"......."
"And over there, our provisional student council members are..."
"You've been awfully noisy for a while now."
"As I've said before, we're only here until the [Book of the Dead] ritual is complete..."
"Mukuro and Kirumi~!"
Then they noticed Ikusaba and Tojo standing in the corner of the room, radiating a murderous aura, and were shocked for a second time.
"Um... why did the student council suddenly get so many more members?"
"Hmm... why indeed~? I think it's because of what the [Book of the Dead] ritual involves~!"
"What the ritual involves?"
"That's right~! According to this book... one of the things we have to do to bring K-kun back to life is spirit channeling~!"
"Indeed... to think the spirit channeling method for the 'Caged Child'—something I've long wished to try—would be included in the [Book of the Dead]... It feels like a cruel twist of fate..."
As Angie and Shinguji laughed in unison, a sinister aura entirely different from the one surrounding Ikusaba and Tojo began to seep through the room. In an instant, the lab was saturated with a truly dreadful atmosphere.
"And... Mukuro and Tojo were so worried about K that they volunteered to become provisional members too~! Well? Isn't our student council amazing? You want to join too now, don't you~? Right~?"
"Ahaha... well... not really..."
"Then maybe... you're planning to join the anti-student council faction~?"
"N-no! That's not it at all!!"
When Angie fixed them with a cold smile, Saihara hurriedly denied it, visibly rattled.
"Nyahaha~! Then that's fine! The [anti-student council faction] that defies God's will is going to meet a miserable end later anyway~ so you absolutely mustn't go near them~!"
"R-right..."
That was the last straw. Unable to endure the ominous pressure filling the lab any longer, the three quickly left the room.
"Do you really think K-kun can be brought back with something that occult...?"
"Yeah... honestly, I think it's impossible. But still... we're in a situation where we have no choice but to pin our hopes on even that kind of miracle."
"Well, we'll know the truth tomorrow. We've done everything we can, so... how about we call it a day and get some rest?"
Judging that there was nothing more to learn, the three said their goodbyes and split up.
'...Idiots.'
And at that very moment, one of the three was inwardly mocking the other two.
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In the dead of night, while everyone else slept, a man stood in a remote corner of Saishu Academy's back courtyard.
Rustle
"...You came?"
When the unusually short man muttered in a low voice, black silhouettes began to emerge from the grass.
"So you're all here. Everyone, thank you for handling this so well. Thanks to you, everything was able to proceed according to plan."
Even in the thick darkness, Hoshi Ryoma somehow managed to count the people gathered there.
"Then this time..."
He quietly glanced down at his E-Handbook, then lifted his head and looked at the shadowy figures.
"...You'll need to put in some work during tomorrow's [Book of the Dead] ritual."