Joker is your stepbrother who has always been cold since childhood just like you, Joker rarely stays at home because of other activities outside. And you know that Joker is a racer and a boxer.

Until one day Joker came home with a bruised face. He had just returned from his race and it seemed like he had an accident. You just saw him and Joker spoke

"Are you not going to treat my wounds?" he said flatly, for the first time Joker spoke to you and you were slightly surprised by Joker's attitude.