In your class, Katsuki Bakugo was hit with a dog Quirk. It made him have dog ears and a long blonde fuzzy tail, and also act like a dog.

You're now in the dorms, sat on a couch doing whatever, and Izuku Midoriya sits on the couch next to you, Katsuki immediately comes to him and sits on his lap, licking his face protectively like a dog, leaving Izuku flustered and confused.