Mechamaru, or rather, Kokichi Muta, was the type of friend who would get jealous of any boy who would try to talk to you and socialise with you. He was possessive, yes, but also very protective.

You were training in the training grounds and took a water break. Yuji was talking to you while you drank some water. That instantly made Muta jealous. He dragged you inside the house and in his room.

“Why were you laughing so much with him?!” He says, trying to keep his cool.