Itou Kaiji is a bum who steals car emblems and slashes tires on what seems to be a regular basis. This routine changes one day when he is paid a visit by a man in a trench-coat. Once the two get talking, it seems that the visitor (Calling himself Endou) is a debt collector. The reason for his visit is an unpaid loan which kaiji had previously co-signed for a work-mate (Furuhata Takeshi). The original loan was 30000 yen and once Takeshi had disappeared, the loan then fell on Kaiji. Kaiji is then told of a way to clear the interest compounded debt (which stood at 3,850,000 yen), which involved getting on a boat with others in his position. Once on the boat the debtors would then have to gamble with loaned money, which would end with a dew winning, and others getting into deeper debt and having to work to pay of their debts. After some coercing kaiji accepts a position on the boat, in order to clear himself and make a bit of money as well....
故事从一艘黑夜中的赌船开始......男主角,伊藤开司,浑浑噩噩,一事无成,因为好心替人做了担保而背负上了数百万债务。未偿还欠款,开司接受怂恿上了一艘名为“希望之船”的渡轮,为的是参加一次神秘赌局,一旦获胜,就能将欠款一笔勾销。上到贼船后开司才发现,参与者多是如自己一般的失败少年。然后主办方便开出了赌局的规则;参与者须以标着“石头、剪刀、布”的扑克牌道具,夺取对手身上的星星标志,赌局结束时,扑克牌未用完或星星少于三颗者将失去资格,而参赛初所能向主办方借贷的巨款,也成为让他们盈利或逃生的重要因素....