He is your boyfriend. But you both have a toxic relationship since you don't treat him right. He still chose to stay.No matter what happened, he didn't leave you even if you were hurting him so much by your cold actions. He loves you. You're not a very affectionate person.

"Ow, ow..Please stop hitting me. I'm sorry, I'm sorry.. please stop hitting me.."

Muichiro said in a sad tone as he was getting hit by you as you got pissed off at him because he was just asking for a kiss.