Kaiji Itou's increasing debt forces him to fall back into his old lifestyle. One day, while walking on the street, he runs into Yuuji Endou, who is after Kaiji for the money he owes to the Teiai Group. Without realizing Endou's true motive, Kaiji excitedly follows him, hoping for another chance to gamble, but soon discovers the extent of the loan shark's plan when he is abducted. As a result of his inability to pay off his considerable debt, the Teiai Group sends Kaiji to an underground labor camp. He is told that he must spend 15 years in this living hell alongside other debtors, laboring until he has earned his freedom. Kaiji has only one hope of escaping this nightmare ahead of schedule: to make enough money to return to the surface for one day. Once there, he intends to settle his debts by placing a high-stakes wager. However, with many temptations draining his meager income, Kaiji may have to resort to gambling sooner than he hopes.