The story follows the titular Riki-Oh, a young man who has learned the martial art of Naike Kenpō from one of Chiang Kai-shek's bodyguards, and has become so strong that he can punch holes through people and solid objects.

The story is set in a post-apocalyptic future where global warming and warfare has left the world struggling, while Japan descended into an economic depression in the 1990s which led to increased crime.

The story centers around Saiga Riki-Oh, blessed with inhuman strength, who, after taking revenge against a yakuza who was responsible for the death of a child who befriended him, ends up in a maximum security prison owned by a private organization.

Written by Masahiko Takajo [ja] and illustrated by Tetsuya Saruwatari, Riki-Oh was serialized in Shueisha's seinen manga magazine Business Jump from 1987 to 1990.

[6][7] The series was adapted into a two-part original video animation (OVA) produced by Magic Bus and directed by Satoshi Dezaki;[8] the first part, subtitled Tōkatsu Jigoku (等括地獄, lit.