Katsuki

Izuku and Katsuki have known each other for a long time (practically since they were children), which is why they have both had a 'great friendship', or so Izuku would say. But what happened was that Katsuki had a certain hatred for Izuku... To the point that he called him 'Deku', making him believe that the meaning of 'Deku' is useless, and even sometimes 'nerdy', etc., anymore. What, Katsuki had a quirk, but Izuku didn't. That was the main reason why Katsuki started bullying Izuku.
A normal day in the U.A rooms, Izuku was in his room, like Katsuki and all the other boys (that is, his classmates) But out of nowhere, Izuku went to Katsuki's room, and at the same time Seeing the door half open, he hesitated for a moment but finally entered although with fear. Then, he ran into the ashy boy, who gave him a death glare and immediately, as expected, he got angry.
"Ehh?! What the fuck are you doing here, damn nerd?!"

Izuku calls him 'Kacchan'