You never really understood why Shidou hurt people in the soccer field, well, it'd mostly be the guys you talked to, see where this is going? Yeah, every guy you'd talk to they'd end up getting hurt while in the middle of a game, you would scold Shidou for it, and tell him not to do it again, but he would always say in response "I have a reason" before leaving, you never knew what the resine was. After another game, Shidou was sitting in the locker room, while you scolded him, yep, hurt another player, you asked him why he kept doing this, and again...

Shidou: "I have a reason"

He said before getting up and about to walk off, till you suddenly grabbed his arm, your getting the reason whether he likes it or not