The Exchange Program(an Assassination Classroom/Saiki K. crossover)

Prologue

"Karma Akabane and Gakushu Asano, you two have been chosen to take part in an exchange program at PK Academy. Please behave yourselves there, and make our school proud," the form teacher instructed.
"PK Academy, huh?" Karma smirked as he and Asano were handed their school uniforms and handbooks. "This is gonna be quite interesting, ne?" He commented snarkily as the orange-haired teen huffed.
"Don't do anything to disgrace our school's name, Akabane, or you'll know what'll happen," he warned. "No worries! I'll make sure there's no one beside me first..." Karma murmured loud enough for Asano to hear what he was saying.
"Why you..." The red-haired devil snickered as his companion glared irritatedly. "Do you want to get suspended?" Asano quipped as Karma stuck his tongue out. "Just kidding. You have no sense of humour, Asano."
"Why, I do. In fact, it'd be fun if you got into trouble on your first day," he commented sarcastically as they entered the toilet. "I know, right?" Both of them entered a cubicle, and changed in silence.
"...I can't tell whether you meant that, Akabane. But seriously, don't give me any funny business," Asano ordered as he emerged in the standard PK uniform. Karma opened the door beside, but he was still dressed in his black jumper.
"Eh~? I thought I'd have some fun while I'm there," Karma leered as their class waved them goodbye. "I'm saying..." The unofficial leader of Kunugigaoka rambled on while he took a selfie to send to 3-E.
"Going to PK Academy later!" He texted. Most of his ex-classmates replied with "that's great!" or "good luck!" He smiled, satisfied as the bus soon came for them to report. "Ne, Asano." Karma sprawled onto the seat as Asano checked the new timetable.
"Hn?" "You still wanna compete for midterm after this?" The troublemaker teased as the other almost dropped his phone. It remained a sore subject(but only for Asano) for he had never managed to beat Karma ever since.
"Do you want to die, Akabane? Of course, I won't lose this time," he snapped as Karma continued texting his friends. "Plus...you haven't told me ANYTHING about that supposed 'Koro Sensei'," he added.
"Oh? Must've slipped my mind." The redhead began playing a game this time, but in truth he was still affected. His teacher, whom they assassinated two years ago, played a big part in what he is now. "I wonder what he'd say to me..." he thought.
"We're almost there," the bus driver informed. Karma looked up from his phone as the school they're going to stay in cane into view. "So, this is our new playground, huh?" He grinned as Asano smirked as well.
"PK Academy...here we come."

...................................................................

In PK Academy, Saiki felt a chill down his spine, causing him to immediately request to go to the bathroom. "Huh? There's exchange students coming?" "Oh man, please don't give us any more weirdos."...The class started to murmur as their teacher gestured for the students from Kunugigaoka high to enter the classroom. A redhead and a strawberry blonde then stepped inside and introduced themselves.
"I'm Karma Akabane! Nice to meet ya!"
"I'm Gakushu Asano. I hope we get along..."
The class was elated that they seemed normal, but Saiki just sat in the toilet blaming his bad luck.

"These people are bothersome. Yare yare, what do I have to deal with now...?"