Kyoko did not enjoy sleeping in Byakuya's room. He had flat out refused to move into her room, so she was stuck sharing his. And while her room was practically bare, his was ostentatious, filled with paintings and a formally set table and even what looked like a coin collection. And of course Byakuya had taken precautions before sleeping in the same place as her, lining his side of the room with a labyrinth of strings attached to glassware so that she couldn't approach him without hitting a string and breaking something to alert him. So, Kyoko found she often lay awake for quite some time in this unwelcoming environment, pondering their circumstances, with only Byakuya's light snoring across the room for company.

For that reason, she was quite disgruntled when she was woken up in the early morning after only having had a few hours of sleep. By Monokuma…

When Kyoko asked him what he was doing in the room, he said some nonsense like usual that basically amounted to "one of your classmates is dead," then ran away laughing. Kyoko sighed, more annoyed at the killer than anything, both for killing with such a small chance to get away with it given the number of confessions yesterday, and for indirectly interrupting her sleep.

She got up, before noticing that Byakuya was not in his bed, and his string maze was taken down. Her eyes widened as she began to wonder if Byakuya had somehow gone out and gotten himself killed in the middle of the night, so she quickly got dressed and left… only to run into Byakuya standing in the hallway outside his door.

"Oh, good, you're finally awake," he said haughtily.

"What are you doing out here?" Kyoko asked, her face expressionless once more.

"Waiting for you, obviously," Byakuya replied. "You did insist on this partner thing, remember? Though I do seem to recall you promising it wouldn't slow me down…"

Kyoko sighed. "I suppose I should clarify that I won't as long as I am awake. I appreciate your waiting for me while I slept."

"I didn't ask for your appreciation," Byakuya replied simply, then began marching down the hall.

Kyoko quickly followed beside him. "So, who died where?"

"Don't know yet," replied Byakuya without slowing or looking at her. "A couple of the others passed me in the hall, they're searching the rooms in pairs, so we will too."

"Alright," said Kyoko. "Let's begin."

…

They found the body in the girls' locker room. It was Chihiro.

They waited until everyone gathered there. Naturally, suspicion immediately fell on Mondo, as he was Chihiro's partner, but Kyoko cautioned them against jumping to conclusions. Particularly troublingly: the word "bloodlust" was written in blood on the wall, which Hina said was the mark of the serial killer Genocide Jack. Monokuma showed up and talked some nonsense, before adding a new rule that the blackened may only kill up to two people, to assuage concerns about a serial killer.

Byakuya was strangely invested in Kyoko's investigations, asking all sorts of questions, interacting much more than he usually would. Perhaps he worried she would suspect him? She answered his questions honestly and they examined the body, the crime scene, and the surroundings thoroughly, and Kyoko also got more details about Genocide Jack from Hina.

Going into the trial, Kyoko was pretty sure she knew who the culprit was. She figured out Chihiro's secret immediately once she examined "her" body, which led to her discovering the switched locker room signs. So it was a man who hadn't shared his secret and who could get Chihiro alone. Really, it was a disappointingly easy case.

The others didn't seem to think so when the trial started, but they were distracted by the Genocide Jack trappings. Kyoko was confused by them too, but either the killer put them up as a distraction or somebody else did, and while Mondo didn't seem the type to utilize misdirection, who else could possibly want to make this more convoluted?

Oh, right. Byakuya.

As the trial discussion progressed, it turned out that yes, Byakuya had gotten up early to investigate alone and had been met by Toko who had gotten up early to speak to him. She confessed her secret to him, and later he came across Mondo leaving the girl's locker room. He entered it, saw Chihiro, and used Toko's secret to make the trial more interesting.

"I thought you'd appreciate it, Kirigiri," Byakuya said, smiling smugly. "A game's no fun without a challenge, and clearly more would have been required to challenge you."

Kyoko didn't want to admit it, but a part of her did actually appreciate it. She enjoyed the puzzle-solving, and it's not as though Byakuya would have let the ruse go on to the point where they all died, including himself. But under these circumstances? "I'd rather the trials were boring," she said calmly. "It's not my entertainment you should be worried about. It's his." She pointed at Monokuma.

"Hah! As if I could ever get bored of watching you cuties murder each other in cold blood!" laughed the bear. "Oh, nothing gets the blood flowing quite like flowing blood, wouldn't you agree?"

Blegh. Anyway, she was able to quickly get the rest of the group on board after that. They'd all been suspicious of Mondo in the first place anyway, since Chihiro was his partner and he hadn't shared his secret. Taka was the exception, and he tried to defend his friend right up until Mondo admitted defeat and confessed the whole story. As might be expected, it wasn't a thought-out killing, Mondo just let himself be caught up in his tumultuous emotions of fear and guilt and jealousy (Chihiro had confessed "her" secret to him and he couldn't bring himself to do the same) while talking to Chihiro and helping "her" train, and he lashed out without thinking. He even shared the secret he'd killed to protect, which was that his brother had died to save him after he put himself in danger, and he felt responsible.

Monokuma executed him by spinning him in a wheel until he melted, and while Kyoko didn't want to think ill of the dead, especially given that he did not ask to be here, she couldn't help but be disappointed in how senseless and avoidable Mondo's murder was. Poor sweet Chihiro died for nothing.

"Well, congratulations to those who didn't share their secrets yesterday," she remarked as the group rode the elevator back to the dorms. "Guess you won't have to reveal your secrets after all."

"At this point, only me and Celeste keep our secrets hidden," Byakuya commented. "And Sakura, I suppose. But yes, it seems like once again your little exercises failed to prevent a murder."

"They would have if Mondo was thinking rationally," Kyoko countered. "As it was my tactics that made it so easy to identify him."

Kyoko knew what this was really about, of course. As the others watched in mournful silence, Byakuya and Kyoko vied for their respect. Both wished to be seen as a leader, neither wished to lose face. Kyoko thought that might have been the real reason behind Byakuya's Genocide Jack ploy: to be seen as an active player in the game, someone to notice and respect, rather than just someone else who follows where Kyoko leads.

"Speaking of people thinking irrationally," Celeste said weakly. "Do I have to stay with her?" She pointed at Toko, who was still sticking her tongue out and twirling a pair of scissors she'd gotten who-knows-where.

"If you do, you'll have to follow Master, cuz that's what I'll be doing, Bwahaha!" Kyoko winced at Toko's ear-splitting laughter.

"As if I would allow that," Byakuya scoffed.

"'Master'?" Kyoko repeated, giving Byakuya a questioning look.

He shrugged. "Toko warned me her other personality would go for me. Apparently I'm 'her type.'"

"Oh yes, I'd do anything for Master!" Toko said cheerfully.

"Including locking yourself in your room and leaving me alone?" Byakuya retorted.

"Nope!" Toko replied.

"Perhaps… perhaps you and I should pair up instead, Celeste," Kyoko said.

"Happily," Celeste replied.

Byakuya raised an eyebrow at Kyoko. "Already decide you can't keep up with me, Kirigiri?"

"Hardly," she said. "But I suspect you and Toko will end up keeping track of each other's whereabouts, whether you're paired with someone else or not."

"Shouldn't we, like, tie her up or something?" Hiro asked quietly as the elevator came to a stop and they walked down the halls. "We don't want a serial killer running around freely."

"Hah! I'd like to see you try!" Toko shouted, brandishing her scissors at Hiro, who cowered.

"Genocide Jack…" Kyoko began.

"Genocide Jill!" Toko cut in.

"Sure," Kyoko replied without missing a beat, "She only kills young pretty boys, and only in a particular way, using tools she doesn't have access to in here, right?"

"That's right!" Toko smiled. "Killing is an art, and this painter doesn't have her paintbrushes!"

"So none of us have anything to fear," Kyoko commented calmly. "Except maybe Byakuya, though from the sound of it he should fear more for his sanity than his life." The hint of a smirk appeared on Kyoko's face as she looked at Byakuya.

Byakuya rolled his eyes, and marched further ahead of the group, entering his room. Toko rushed after him and hammered on his door for quite some time. The others still didn't seem comfortable with the idea of Toko running free, but no one wanted to deal with it right now. Kyoko especially did not want to try to enter that room to retrieve her things tonight, and instead she recruited Sakura to help her grab Chihiro's old bed to take into Celeste's room (she had pocketed Chihiro's room key when she examined "her" body, as she had Sayaka's, though she couldn't find Junko's. Never know when you might need access to someone's room for an investigation, she had thought).

When she finally lay down, she fell asleep immediately.

…

A/N: Unfortunately, both Leon and Mondo's murders were done out of rage and desperation without thinking of the consequences. They weren't motivated by rational considerations, so I think it stands to reason that Kyoko's efforts would not stop them, just make them easier to identify. Future canon murderers are more rational with their approach and motivations, so this is the last trial that will run identically to canon.