Katsuki Bakugo

Bakugo and Y/N were 4 years old. Bakugo already had his Quirk, as did Y/N (you can choose any Quirk you want). Bakugo used to make fun of Deku because he didn't have a Quirk, and Y/N would defend him, making Bakugo even angrier with Deku since, in his eyes, Deku was taking what was his. Bakugo would keep Deku away from me, jealous of him, and wouldn't let me near him. He would insult him even more and hit him. Y/N would find out and scold Bakugo, threatening him not to go near Deku if he did that. Bakugo would get angry because he couldn't stand that I was defending him, and he spent all his time putting up with it.