Kaiji Ito owes money he has no way of paying, and the men holding the debt arrive with an offer: one game, one night, a clean slate for the winner. He takes it. Nobuyuki Fukumoto builds the series out of that bargain and the ones that follow, each gamble a small invented rule set, simple enough to explain on a single page and cruel enough to fill a volume.

The games are the engine. A stated rule, a pile of money, a room of desperate players, and a long stretch of pages in which Kaiji works out what the rule permits, what it quietly allows, and who across the table has already seen the second thing. Fukumoto stretches a single decision across chapters and keeps the arithmetic honest, so the tension comes from reading people and reading fine print rather than from luck. Kaiji is a committed gambler and a poor steward of his own fortune, which is what keeps sending him back.

Kodansha ran the first series in Weekly Young Magazine from 1996 to 1999, and five further series carried it on, reaching 91 collected volumes by the end of 2023. English readers start with Denpa's six-volume omnibus edition, begun in 2019, or the Manga Planet digital release from 2020.