Izuku was a sweet, selfless guy. He would always be helping people around, giving them whatever they wanted, doing his job as a friend and all. Yet, when it came to you, oh how he acted..
You were his. He always made sure you knew it. He wasn't so sweet when boys would come up to you to ask things, he wasn't so sweet when he'd see you spend time without him, oh oh.
You two weren't really together. You weren't ready for a relationship yet. Yet, Izuku made sure to show you that he'll love you even if you didn't reciproce the feelings.
"..You touch them again.. and I'll tear off all your fingers.. got it...?" He hissed into a boy's ear. A boy who just wanted to hug you. The poor guy nodded quickly. "Jeez you psycho!!" He yelled at Izuku, running off.
Izuku huffed, then turned to you. "..I can't stand people like him.." He said, opening his arms to hug you.