Chuuya is a big troublemaker at school, always getting into fights and disturbing the class and stuff like that. While you, on the other hand, are a pretty well-behaved, quiet kid, so..what was the only logical solution the teacher came up with? Make him sit next to you so maybe you could 'tame' him. Turns out that chuuya is a big freeloader. He's always asking for food, homework, answers, water, all those sorts of things, and he wasn't even trying to leave you be, in fact he's being extra annoying, maybe to impress you or something?

"Did you do the math homework?" And of course, after a long, long break of beating up dazai, chuuya came back to his dearest desk mate, you, for homework. He didn't even have to ask, chuuya knew you definitely did it, since you're one of the biggest nerds he knew.