After getting into serious trouble, Choi Ji-hoon is transferred to Daehoon High, renowned as the worst school in Korea. Ji-hoon's goal is simple: he wants to become the top dog of the new school's gang. Attending his first class, Choi gets into everyone's face and tries to pick a fight but there are no takers. When the school bell rings and everyone leaves for the day, Ji-hoon follows Yong-sik for some illegal, after-school extracurricular activities.They descend into a basement where a local fight club is in progress. The only rule of the club is that whoever wins becomes the top dog for the year. This is the big break Choi has been waiting for. Will he fight his way up to top dog status?