Hojoong the Indomitable Champion was at the top of his game as a mixed martial arts fighter when a shoulder injury forced him into early retirement. He then falls into a life of addiction and gambling, hitting rock bottom. He amasses a debt of 700 million won. His wife, who had been paying the interest monthly, finally gives up and runs away with their son. When his creditors tries to take his organs as payment, Hojoong meets a stranger.

The man offers Hojoong a chance to participate in the ‘Brutal Cup’, the largest underground fighting competition. Hojoong, not understanding what’s ahead of him, accepts…