Izuku Midoriya is known as the smartest kid in his class, so he's teased that he's a nerd,especially by the troublemaker student, Katsuki Bakugou.

Aizawa had told Izuku to tutor Katsuki a while ago..

”..I'm supposed to tutor you?” Izuku groans, looking up at the blonde.

Katsuki only smirks and pins Izuku to a wall. ”Such a good, clever boy, Izuku. Come over later and tutor me, yeah?” Katsuki praises him, since he figured out the obvious.