The Kaiji manga series (and its anime and film adaptations) features an extensive cast of characters created by Nobuyuki Fukumoto.

Kaiji Itō

is a young gambler who moves to Tokyo after high school, where he spends his days drinking and vandalizing cars. When coerced onto the gambling ship Espoir to settle a coworker's debt, he enters a world of high-stakes gambling. Despite his lazy, self-indulgent nature and lack of life goals—traits that earn him the derogatory label "human scum"—Kaiji demonstrates extraordinary courage and strategic brilliance in life-threatening situations. His gambling addiction dates back to high school, where he frequently arrived late while spending excessive time and money on pachinko and pachislot machines.

Kaiji possesses remarkable resilience, described as "a man who can get up at the last minute" and capable of defeating formidable opponents like Tonegawa and Hyōdō. While fiercely loyal to those he trusts, he has suffered repeated betrayals that leave him increasingly cynical. Despite his hardened exterior, he frequently risks personal gain to help others in desperate situations, displaying a paradoxical mix of kindness and naivety.

His gambling prowess earns him legendary status in the underworld, though he consistently finds himself pitted against the Teiai organization. Kaiji recognizes this inescapable connection, yet continues to seek out dangerous games despite the consequences.

Teiai Group Yūji Endō

serves as president of Endō Finance, a Teiai Group subsidiary that operates as a predatory lending operation with exorbitant interest rates. He first appears collecting a debt from Kaiji, subsequently luring him onto the gambling ship Espoir. As a member of Tonegawa's faction within Teiai, Endō's position declines following Tonegawa's dismissal. He later sends Kaiji to an underground labor facility per Teiai's strict policies.

During Kaiji's battle against the Bog, Endō provides additional loans while secretly planning to exploit their agreement. After their victory, he drugs Kaiji and Sakazaki, then enforces a crushing 30% interest rate compounded every ten minutes. Despite this ruthless action, he shows unexpected restraint by adhering strictly to the contract terms and not confiscating Sakazaki's share. In later events, Endō leads Teiai's manhunt operations as head of the Kaiji-Chang-Mario pursuit team.

The live-action adaptation reimagines the character as Rinko Endō, a female Teiai executive who competes with Tonegawa. After losing this power struggle, she finances Kaiji's E-Card battle with similar loan terms, ultimately leaving the organization with substantial funds following Kaiji's victory.

Yukio Tonegawa

is a high-ranking Teiai Group executive and Kaiji's primary antagonist in the series' first part. He oversees deadly gambling events, using ruthless rhetoric to manipulate debtors. A cunning strategist, he disdains weakness and remains unmoved by their suffering.

Kaiji defeats him in the E-Card game by exploiting his overconfidence, costing Tonegawa his position. As punishment, he endures the Grilling Grovel, lasting an unprecedented 12.47 seconds before being cast out of Teiai. His later fate is unclear.

A prequel spin-off, Mr. Tonegawa: Middle Management Blues, depicts his earlier career comically. In live-action films, he first loses to Kaiji in Kaiji, then betrays him in Kaiji 2 after a temporary alliance, stealing his winnings but leaving a token sum. The films end with Tonegawa watching enviously as Kaiji celebrates with friends.

Kazutaka Hyōdō

is the ruthless chairman of the Teiai Group and the series' primary antagonist. A wealthy and power-hungry businessman, he seeks to build a financial empire that would sustain him even in societal collapse. A sadist, he enjoys manipulating high-stakes gambles and inflicting suffering on debtors, enforcing brutal penalties such as forced labor, mutilation, or death. Despite his cruelty, he occasionally displays fairness and ethical conflict, such as hesitating over exposing his son Kazuya to violent games. Though he admires Kaiji's defiance, he ultimately views him as inferior and relishes his downfall.

Hyōdō first appears in silhouette at the conclusion of the first arc before directly confronting Kaiji in a high-stakes gamble known as the "Tissue Box Lottery", where he asserts his dominance as the undisputed king of Teiai. In later arcs, he and his organization remain persistent obstacles in Kaiji's path. He is married to Sophie, a foreign woman, and has two sons, Kazuki and Kazuya.

Spin-offs depict him as erratic, often berating subordinates like Tonegawa and imposing harsh conditions on workers.

Gambling Apocalypse: Kaiji / Kaiji: Ultimate Survivor Takeshi Furuhata

is a debtor and one-time coworker of Kaiji, Furuhata is the one who initiated Kaiji's entry into the underworld. He is timid and easily influenced by others. A debt collector encouraged him to make Kaiji his cosigner and he disappears, but is eventually reunited with Kaiji on the Espoir and they fight through the Restricted Rock-paper-scissors gamble together. Eventually, though Andō incited him to betray Kaiji, both of them are punished by the resurrected Kaiji and lose their surplus stars and money. In the end, he could not pay off the debt and ended up saddled with new debts on the ship. His whereabouts after that are unknown. He is only mentioned once by name in the live-action adaptation.

Mamoru Andō

is an overweight, glasses-wearing participant in the gambling tournament aboard the Espoir. He initially allies with Kaiji and Furuhata but quickly betrays them for personal gain. During the final stage of the competition, when tasked with rescuing Kaiji as part of their survival strategy, Andō succumbs to greed and convinces Furuhata to abandon their agreement. His attempt to sacrifice Kaiji for financial gain fails when Kaiji escapes independently. Though Andō survives the event, he incurs additional debts from the ship's operations.

Kōji Ishida

is a deeply indebted middle-aged man characterized by his timid and trusting nature. He joins the Espoir gambling event to repay debts for his wife and son, but is deceived and sent to forced labor. Kaiji, moved by Ishida's genuine concern for his well-being, rescues him.

Later, Ishida participates in the Starside Hotel gambling event, winning a ¥10 million voucher in the first Human Derby race. During the perilous Electrified Steel Beam Crossing, his fear paralyzes him, and he entrusts his winnings to Kaiji to settle his family's debts. Choosing silence to avoid distracting Kaiji, he falls to his death—an act that profoundly affects Kaiji, who admires Ishida's dignity and selflessness.

In the live-action adaptation, Ishida allies with Kaiji on the Espoir and defeats Funai, but an extra card results in his consignment to underground labor alongside Kaiji.

Jōji Funai

is a cunning participant on the Espoir. As a repeat contestant, he uses his experience to manipulate newcomers, notably cheating Kaiji out of two star chips and nearly eliminating him from the competition. Though consistently outmaneuvering other players throughout the event, Funai ultimately miscalculates the game's dynamics. When only Kaiji remains as his opponent, he must accept a high-stakes duel that decides their fates. His ultimate fate after the event remains undisclosed.

In the live-action film adaptations, Funai similarly deceives Kaiji during the Restricted Rock-Paper-Scissors game, but loses when Kaiji discovers his cheating method. The sequel depicts Funai working as a surface agent for the underground operations after his Espoir defeat, where he administers the "Princess and the Slave" gambling event. His attempt to exact revenge on Kaiji during this game fails, resulting in his return to forced labor.

Balance Theorist

The (real name unknown), known as in the anime series and in the stage play adaptation, is one of the participants on the Espoir. He targets opponents with few remaining star chips, earning him the derogatory nickname "Hyena" from Kaiji. His method involves carefully managing his remaining cards to maintain balance throughout the game. When challenging Kaiji, who feigns vulnerability with only one star, the Balance Theorist falls victim to Kaiji's counterstrategy that exploits his predictable pattern, resulting in his decisive defeat.

Kitami

is one of the participants on the Espoirs Restricted Rock-Paper-Scissors event. Though inexperienced, he quickly devises card-monopolization tactics, first targeting rock, then paper cards after Kaiji counters him. When Kaiji outmaneuvers him in a decisive match, Kitami's team fractures due to his arrogant demeanor, leading his partners to accept Kaiji's offer to betray him. Forced to pay ¥2 million to exit, Kitami's defeat demonstrates both his adaptability and his ultimate failure to maintain alliances.

Okabayashi

is a cynical participant in the Espoir gambling event. He deliberately enters the ship's punishment zone to execute a prearranged scam with accomplices, having redistributed his excessive debts to gain entry. While confined, he mocks Kaiji and Ishida for their faith in altruism, praising instead Andō and Furuhata's pragmatic betrayal as natural survival strategy. Okabayashi escapes by concealing jewelry in a bandage, though Kaiji intercepts and claims these valuables at the last moment. This encounter reinforces Kaiji's realization that survival depends on self-reliance rather than trust.

Makoto Sahara

is Kaiji's coworker at a part-time job following the Espoir event. He shares Kaiji's lazy tendencies despite aspiring for success. Though typically talkative and carefree, he demonstrates unexpected mental resilience and physical ability during high-stakes competitions.

Sahara participates in Teiai's Human Derby gamble at Endō's request, winning the initial race. During the second stage, he overcomes hallucinations and fear to successfully cross the steel beam. However, he dies when struck by an artificially created wind gust, a concealed trap set by the organizers. Teiai officially reports his death as natural causes.

Tobaku Hakairoku Kaiji / Kaiji: Against All Rules Yoshihiro Kurosaki

is a high-ranking Teiai Group executive who becomes the organization's second-in-command after Tonegawa's dismissal. Though dismissive of Kaiji as a "stray dog", he acknowledges his gambling skills. Kurosaki demonstrates pragmatic leadership, occasionally showing concern for subordinates while maintaining strict control over Teiai's operations.

A family man with a wife and two children, Kurosaki struggles to connect with his introverted family. He dreams of traveling Japan after retirement. Spin-off media portray him as Tonegawa's straightforward rival and depict his occasional interactions with underground workers.

In the Final Game film adaptation, Kurosaki founds Japan's dominant temp agency, Goodwill Industries, before facing Kaiji in Teiai Land's "Last Judgment" game.

Tarō Ōtsuki

is the foreman of Squad E in Teiai Group's underground labor camp, where Kaiji is assigned. While presenting himself as a helpful advisor to new prisoners, Ōtsuki secretly exploits them through illicit schemes. He maintains his privileged position by skimming profits from wage advances and luxury goods sales while organizing illegal gambling operations under the guise of stress relief.

Ōtsuki orchestrates a rigged Cee-lo game using altered dice that lack low numbers, collaborating with subordinates Isawa and Numakawa to systematically defraud prisoners. His long-term goal involves amassing 20 million perica—the underground currency—to purchase extended surface leave, though his intentions regarding permanent escape remain ambiguous.