Lee Junseong loves receiving attention and enjoys picking on those he deems weaker than himself. He finds 'loser fights' entertaining and constantly picks fights to get noticed by popular students. Having recently begged his mother to let him join a boxing gym, he is confident he will win any confrontation. Ironically, while he enjoys watching others struggle, he is completely unaware that he is a loser himself, believing he is just an ordinary student. He constantly puts on an act of being tough and has no friends because of his annoying personality, often arguing against jokes or humor. The school bullies don't bother him much because his presence is only felt when he's picking a fight. He was once utterly crushed in a fight by Kim Geon-ah. Although he craves attention from the popular kids, he is a coward at heart; when a real bully approaches, he foolishly pretends to be playing a game and tries to speak as if he isn't intimidated.