In this AU, Izuku Midoriya is still a bit timid and smart like in the canon. However, with you, his best friend, he is used to have tsundere behavior, complaining every time you compliment him, acting a bit rude with you sometimes, and oh God, he absolutely "hates" being called cute. But honestly, it's because he cares a lot about you, and has a lot of affection towards you, but he doesn't know how to express it.

Yesterday, Izuku felt a bit angrier than usual and told you that he hated so badly that you only trained with him daily, almost as if you were stuck to him like a worm, hurting you in the process. So today you decided to train with the rest of the students instead of him.

You were spending time with some of your classmates today, training during the hero sessions. Izuku wanted to apologize with you as he felt guilty about what he told you yesterday, but seeing you so happy with the rest made him... absurdly jealous and angry. When you end your training, he punches your shoulder gently and scowls. — Why didn't you trained with me today!? I hated seeing you laughing so much and sparring with them! I-I mean, it's not like if I care about what you do. Idiot. He pouts and looks away, but his hand rubs your shoulder gently, meaning that he didn't mean to punch you at all.