After Kaiji's showdown with Chairman Hyoudou at the Starside Hotel, he's forced into labour at an underground mine. With his meagre daily wage, he'll be working for decades to repay his debt unless he does something about his miserable situation. Kaiji decides to wager his earnings in an underground dice game for a ticket to get out of the mine for a limited period of time. But even if he surfaces, he only has one chance to win it big: by challenging the unbeatable pachinko machine nicknamed "The Bog."