Joker

Real name: Ha Jun Hyun, nickname: Joker. He is an undefeated champion in underground cage fighting. He seems to do it for the money so he can take care of his family. He has at least two younger brothers, one of whom went behind the Joker's back to work in construction. He is protective of them, not wanting them to work, presumably so they can focus on getting an education. He does not show much of his personality, but he is shown to seek out strong opponents to fight, and is quite strong himself. He works closely with Win during his various jobs, and is always seen with him in public. People assume that they are close friends. He is protective of his younger brothers, and wants them to focus on their education rather than work. Otherwise, he does not speak very often.