Not taking things seriously

Students all gathered and watched as the principal was taken away in a body bag. Frantic staff members and teachers desperately tried to control the crowd, but to no avail.

"My, seems that foul celebrity, Mimoko Inoue, drove our poor principal to suicide Shion Segawa sneered.

"Yeah, she even called him up to the roof, I saw it!" Kigyoku Gyakui sneered.

"Bullshit! I was in class the whole time!" Mimoko fumed.

"Was she really?" Shion sneered as she gazed at Mimoko's teacher.

"Um, she... Left the room for a period of time."

Mimoko was taken aback. "I was there the whole time!"

"Lying is a crime. A crime which Governor Segawa can EASILY punish you all for," Shion sneered as she gazed at the students from Mimoko's class.

All the students looked uneasy and terrified. Mimoko quickly surmised Shion had threatened them and the teacher.

"Hey motherf*****! I got proof of innocence!" Iori glared as she whipped out her phone. "See, Mimo-chan's right there. You can even see fatso fall. Wish I knew it was happenin’ so I could've seen the splat."

Shion began to scowl as she shot a murderous glare towards Mimoko’s teacher. Before she could do anything though, Kazuya stepped forward.

"Allow me to enlighten the crowd with my theory of events. I investigated the roof, and found this chess device strewn about it," he stated as he pulled out a DESPER.

The 5 senior members of the chess club instantly recognized the device, however no one else showed any reaction towards it.

"I see you are all confused. Allow me to enlighten you all. This device can force you to play a chess match with the penalty of death should you lose. Consumed with their newfound fame and influence, the Mimoko Inoue led chess club hatched a plan to assassinate our beloved principal with this heinous device."

The crowd descended into gasps and murmurs as Kazuya stared at Utami. "Wh- Why are you staring at me?" Utami trembled.

"Because you're a suspect, dear sister. I believe you and the chess club also used this to kill dear Nagi and Manabe-san."

"That was Gyro's DESPER that created the bughouse arena. Besides, everyone agreed to it, and even your father had no qualms about Nagi's death," Okisato stated.

"So this is called a "DESPER" then. Well, of course you would know its name; it's yours after all."

"No it isn't. In fact, I bet someone's trying to frame us."

"Who? The "Gyro" you spoke of?"

"No, he's dead, but maybe one of his buddies or someone he recently got in good graces with," Okisato said as he turned towards Shion.

"My, leveling slander against me? Seems you want life in prison," Shion sneered.

"And what exactly did I say against you?"

"Implied slander is still slander. Now, why don't we continue this discussion after you're all secured in an inescapable holding cell."

"How about no. Sensei! Can we go home early?" Okisato shouted at a teacher.

The crowd immediately began echoing Okisato's sentiment as the teachers reached their breaking point. "EVERYONE GET BACK TO CLASS NOW! THERE'S STILL AN HOUR LEFT OF SCHOOL!" one of the senior teachers shouted.

"No, I think it would be easier for all of us if we cleared the school of students. They would only get in the way of the police," Maida argued.

"Any witnesses would need to stay for a bit, but it would be easier for us not to have so many people here," the officer stated.

The staff agreed to go with Maida's proposal and school was dismissed for the day. Some students were required to stay for a bit and give their testimonies, but after that, they were allowed to leave.

…

"Ugh, my mind is at its limit," Mimoko groaned as she sat down at a bench in the park.

"Club activities were also canceled for the day, so we don't need to have an unofficial club if you're too tired," Okisato nodded.

"I'm frustrated; and when I'm frustrated, I want to play chess."

"So I'm the unlucky sandbag then."

"If I went home, I'd have to play online, since my family doesn't play chess, but I can't air my grievances with a complete stranger."

"Then let it out," Okisato said as he let out a heavy sigh and moved his pawn to a4.

"As soon as we were ordered to leave, Utami-chan was swept away by that asshole student council president," Mimoko said as she moved her pawn to d5.

"Her brother? If I remember correctly, he’s been absent for the past week, but the reason wasn't given. Though I believe he’s the one dating Shion Segawa."

"You think she's behind this?"

"Yeah, me, Zenihara-san and Shousen-san were in class with Maida-sensei. You and Iori-chan were also together," Okisato stated as he moved his pawn to b4.

"But what about the 1st-years and Numakawa-kun?" Mimoko asked as she moved her bishop to f5.

"That's the weird thing. Apparently, only you, me, Enoki-san, Shousen-san, and Maida-sensei were pulled aside for additional questioning. In fact, I'm not sure if Segawa is even aware that we have more members. Zenihara-san is in the same class as me and Shousen-san, but wasn't accosted by Segawa and her group."

"But we all ate lunch together."

"It isn't definitive proof. I also found out there wasn't a group photo of us winning the team award so it's possible to just count the incident as pure coincidence," Okisato said as he moved his pawn to c4.

"Still, I don't like having enemies that make our club members feel uneasy. Iori-chan really hates Segawa you know," Mimoko said as she captured the pawn at c4 with her d-pawn.

"Why's that?" Okisato asked as he moved his pawn to d4.

"Apparently she's bullied her for years due to her being poor," Mimoko stated as she performed en passant and captured the pawn at d4 with her c-pawn.

"Iori-chan's poor? I thought she was making decent bank with her streaming career," Okisato gasped as he moved his pawn to e4.

"Well, she was really poor before she started streaming. She also had it rough when her mother and little sister died a few years ago."

"What happened?" Okisato asked as Mimoko captured the pawn at e4 with her bishop.

"She never told me, and I didn't pry. I'd never seen her so consumed by grief," Mimoko said as Okisato moved his pawn to f4.

"Guess under all that pizzazz, she's still just a human being," Okisato nodded as Mimoko moved her pawn to e6.

"Yes, now care to explain what you're doing on the chessboard?" Mimoko glared as Okisato moved his pawn to g4.

Throughout the conversation, Okisato had opted to move each pawn up 2 spaces from left to right while Mimoko played normally. In short, he wasn't taking the game seriously.

"I just wanted to give you more time to air your grievances. You can't really talk if we're playing at our best," Okisato said as Mimoko captured the pawn at b4 with her bishop.

"Take the game seriously. I can talk and think just fine even when I'm playing you," Mimoko glared.

"But then we'd just blitz through it. Don't you want to talk?" Okisato asked as he moved his bishop to d2.

"No, I think I'll just go home and shout into my pillow, checkmate," Mimoko huffed as she moved her queen to h4 and stormed away.

"Uh, I think I upset her," Okisato thought as he heard his phone ringing.

The full game:

White: Okisato Tanabe Black: Mimoko Inoue [Informal match]

1. a4 d5

2. b4 Bf5

3. c4 dxc4

4. d4 cxd3(ep)

5. e4 Bxe4

6. f4 e6

7. g4 Bxb4+

8. Bd2 Qh4#