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.

Against all the odds, Kaiji was able to survive the night on the Espoir but he left with a new debt of ¥6,295,000. It's been 4 months since then and all Kaiji has been doing is living a mundane life, working in a convenience store. It all changes when Endou appears before him, yet again, offering Kaiji a ray of salvation.

Kaiji accepts the invitation to the next party at the Starside Hotel and he recognizes a few familiar faces from the dreadful night on the Espoir. Kaiji is really determined this time not to fall for any tricks however the gambling event this time is "Human Derby" which the spectators are gambling on.

Months after the events at the Starside Hotel, Kaiji runs into loan shark Endoh in a chance encounter. Kaiji is forced into labor in the Teiai Group's underground mines to pay his enormous debts. Workers are paid a slave's wage in scrip called Perica, making what amounts to ¥350 a day. Those who save up enough Perica are allowed a one-day furlough above ground. Kaiji resolves to do so, but is soon tempted by the foreman Otsuki.

Kaiji returns to the Sakazaki apartment, only to find it trashed and empty. Sakazaki has taken the last of his money to the race track. Kaiji's plan for revenge involves Sakazaki, so with a plan to beat the Bog, he tracks Sakazaki down at a Sapporo racetrack. Kaiji approaches Endō who is now broke but agrees to fund him, however it will cost ¥113 million including interest plus 50% of the winnings. Sakazaki violently objects but they end up agreeing to split the winnings three ways after costs.

From his descent into the underground hell to his first encounter with the Bog and Ichijou, relive Kaiji's journey and see just how far he has left to go.

Kaiji plays on even though it appears the chances of winning are zero. Meanwhile, Ichijō receives a request to send a live CCTV feed to the Teiai underground forced labor camp and to Hyōdō. Kaiji continues to play, even after losing ¥20 million in what seems a pointless exercise.

Kaiji continues to play, with every ball deflected by the flippers until one ball makes it through to the plates below, the flipper rods bent because the replacement rods installed after Sakazaki smashed the machine were modified by Kaiji. Ichijō starts to panic and then receives a phone call from Hyōdō telling him to let the game continue and not bring the corporation into disrepute, under penalty of death. Ichijō now relies on his three rigged bottom plates to foil Kaiji's chances of winning.

Kaiji has only ¥20 million left to try and beat the Bog, however he is confident as he is aware of how the three bottom plates are rigged. He explained this to Sakazaki when they were at the racetrack. Slowly Ichijō comes to realize that Kaiji managed to not only tilt the machine to increase his odds of winning, but also create a slightly favorable tilt on the casino building. Unbeknownst to him, Kaiji's group had poured 20 tons of water into plastic tanks in a room on one side of the casino building, causing it to subside slightly on that side.

Kaiji's improbable idea of tilting the building to tilt the Bog pays off, and he gets closer to winning with more balls dropping onto the third and final plate. Ichijō contemplates the consequences of losing everything he has and tilts the machine again in the same direction to prevent balls reaching the third plate as Kaiji uses his last ¥10 million.

Kaiji plays on, but he is on the verge of defeat, having lost all his money. He convinces Endō to lend him his last ¥10 million against his better judgement, but at an exorbitant interest rate, and Kaiji returns to the machine for a final assault.

Kaiji commences to play with the last ¥10 million he borrowed from Endō for a final assault, unaware that Ichijō has tilted the machine in the same direction that Kaiji's group tilted the building, thus creating an almost insurmountable tilt on the first two plates. When half of the money is gone, Ichijō gloats to Kaiji that he can never win, but Kaiji says that he knows about the tilt. As the crowd watches, Kaiji tapes three ¥10,000 bills to the glass, hiding the three plates. In frustration, Ichijō rips them off to see a number of balls circulating on the plates because the losing holes have become clogged with balls which are unable to exit the machine. This increases Kaiji's probability of winning, however they still do not drop into the winning hole.

Kaiji realizes too late that the lean they created in the building also tilts slightly to the left, possibly eliminating his chances of a ball dropping into the rear winning hole. Also, with Ichijō now tilting the machine back to the front, the clogged balls may soon drop out. He is now in a race against time before the money runs out. Finally, two balls head for the winning hole, but unfortunately knock each other away.

Kaiji continues to play until the losing holes on even the third plate are blocked; however, Ichijō has the final weapon – air jets around the winning hole to deflect the balls. In the hushed silence, Kaiji hears the sound of hissing air and deduces what Ichijō has done. As Kaiji runs out of balls to play, the Teiai security men in black arrive to take him back underground. Kaiji proposes calling it a draw to Ichijō who refuses, forcing Kaiji to play his remaining balls and pray for a miracle.

Even with the plates filled to the brim with silver balls, Ichijō's secret weapon, the Curtain of Wind, prevents Kaiji from winning and Kaiji has run out of money. As he is dragged away, Sakazaki appears swearing vengeance on the machine, and gives Kaiji another ¥10 million which he again 'borrowed' from the company safe. Kaiji starts playing again with renewed vigor. The bottom plate is now awash with balls, but none can pass the curtain of wind around the winning hole. The machine appears to groan, and with the plate overflowing with balls, some cascade down the winning hole. Horrified that Kaiji won, Hyōdō sentences Ichijō to 1,050 years underground.

As Ichijō is removed by the men in black, Kaiji tells him to fight his way back to the surface for a rematch. Meanwhile, Kaiji's friends cash in the balls he won for a total of over ¥729 million. Kaiji, Sakazaki and Endō settle their debts and split the remainder for almost ¥190 million each, from which Kaiji must pay back his friends in the underground labor camp.