After one of his coworkers fails to repay a debt, apathetic bum Kaiji Itou is pressured by loan sharks to settle the large sum of cash. Since Kaiji has little money and no future prospects of his own, he is unable to return what his colleague borrowed. Faced with massive financial burdens, Kaiji is given an offer to board the illustrious Espoir—it is said that one night aboard the ship, and all of your debts will be paid.