After Kaiji's showdown with Chairman Hyoudou at Starside Hotel, Kaiji is forced into labor at an underground mine. With meager wages each day, he will work for decades unless he doesn't do something.

Now Kaiji must wager his earnings in underground Chinchirorin gambles for a ticket to the rest of the world. But even if he surfaces, he only has one chance to pay back his enormous debt, and that is by challenging the "unbeatable" Pachinko machine, The Bog.