Itō Kaiji is a loser and gambler living in poverty. One day he is approached by a loan shark named Endō Yūji, who tells Kaiji that he owes ¥3,850,000 (around $37,500) for guaranteeing a loan with a former co-worker who has disappeared. Endō gives Kaiji the option of trying to earn all the money to repay the debt quickly by participating in an unknown gambling event on a ship called Espoir. Kaiji reluctantly agrees.