Kaiji Itou is a bum who's been living in Tokyo for 3 years and gambling his life away, then one day a shady man named Endou Yuuji comes to his home asking for Takeshi Furuhata. It turns out that his friend Furuhata disappeared and left Kaiji with the debt of ¥3,850,000, which will take him 11 years to pay off. But Endou has a proposition for him; he wants Kaiji to participate in the gambling event on the Harumi Wharf.