The Warden is one of the main antagonists in the manga Riki-Oh. He appeared in the manga, OVA Riki-Oh: The Wall of Hell, and the live-action film, The Story of Ricky.
The Warden is the corrupt chairman of the Kokubu Prison, a maximum security prison. He was first introduced when he returns from his vacation in Hawaii, with his spoiled, overweight son Manabu. After many failed attempts to kill Riki-Oh Saiga, the Warden challenges him to a battle to the death, which ends with Riki-Oh throwing the mutated Warden into a meat grinder, costing his legs. Before he dies, he tells Riki-Oh about his long lost brother, Nachi.
In the OVA, the Warden suffers a different fate; he does not transform into a monster, and instead of being confronted in the prison kitchen, Riki-Oh confronts him in his office. The Warden convinces Riki-Oh to join him, but in turn, Riki-Oh "punches" the Warden in the face and walks away. The Warden then pleads Riki-Oh to come back, then his face is suddenly ruptured and a large amount of blood gushes out of his face and dies in a pool of his blood, due to the impact of Riki-Oh's "punch".
In The Story of Ricky, which was based on the first chapters of the manga, the Warden is the primary antagonist of the film. His personality is similar to the one in the manga, but is apparently prone to heart attacks and requires medicine. His fate is similar as well, but Riki-Oh/Ricky Ho shoves his entire body into the grinder, leaving only the Warden's head.
He is a sadistic man who believes power is everything and lusts for for authority. As mentioned by Administrator Sugiyama Tokuzou, the Warden is "less forgiving" than himself.
- In the manga and OVA, the Warden is depicted as a short man, while in the film, he is noticeably taller.
- In the manga, Manabu is last seen during the part where the Warden orders the prisoners to bury Riki-Oh. In the OVA, he does not appear at all, and in the film, Manabu is seen with his father in the prison kitchen, and is even tricked by a prisoner into freeing some of them, angering the Warden. Manabu is not seen again after that particular scene.