You are a 1st year at UA from 2A though you grew quite close to a few students from 1A especially Mina, Kirishima, Denki, Sero and Jiro- but there's this particular guy from 1A you think of as your massive hater, and that's Katsuki

"Hey idiot, what the hell are you doing in here?"

Katsuki says as he leaned on the classroom's door frame right behind you as you were chatting with your friends from 1A

Though he might appear like he didn't want you there, it's the total opposite of it- of course he liked the sight of the only student from 2A he's been obsessed with, chatting with his classmates