Yakuza

Yakuza is cruel, exploitative, opportunistic, and contemptuous of the people beneath him. He praises Denji for being obedient but openly compares him to a dog and admits that he dislikes dogs.

He treats Denji's poverty as leverage, forcing a child to repay a debt that did not originate with him. The old man's willingness to exploit Denji continues even though Denji has repeatedly risked his life hunting Devils for the organization.

His greed eventually extends beyond ordinary crime. The Yakuza want greater supernatural power and accept a bargain without understanding how completely the Devil involved intends to use them.

Yakuza possesses no personal supernatural ability during most of his appearance. His power comes from leadership over an organized-crime group, access to armed subordinates, and control over Denji's inherited debt.

The Yakuza organization later forms a contract with the Zombie Devil in exchange for greater power. Rather than simply empowering them, the Zombie Devil transforms the members into zombies under its own control.

As a transformed zombie, the old boss possesses the basic physical threat associated with the Zombie Devil's servants but loses meaningful independence.

After Denji's father's death, Yakuza informs the young boy that the debt must still be repaid. Denji consequently begins selling body parts, hunting Devils with Pochita, and living in extreme poverty while nearly all of his earnings disappear into repayments.

The boss later brings Denji and Pochita to what appears to be another Devil-hunting job.

The assignment is a trap. The Yakuza have contracted with the Zombie Devil and betray Denji because their new master wants Devil Hunters killed. Denji and Pochita are dismembered, but Pochita subsequently revives Denji by becoming his heart.

Chainsaw Man destroys the Zombie Devil's forces, including the transformed Yakuza. The boss's death later becomes the motive used by his grandson, Katana Man, to justify attacking Denji and Public Safety.

Denji is Yakuza's exploited debtor and Devil Hunter. The boss forces him to repay his father's obligations and eventually betrays him to the Zombie Devil.

Katana Man is Yakuza's grandson. Katana Man remembers him fondly and seeks revenge against Denji after learning of his grandfather's death.

Zombie Devil contracts with the Yakuza organization and turns its members into obedient zombies rather than simply granting the power they expected.

Pochita hunts Devils alongside Denji while the pair work under Yakuza's control.