A world of heroes and villains. Each side fights for their own sense of justice. The setting is close to the modern era, with the major difference being that beastfolk and dragonfolk are a common sight. Hero organizations are mostly managed as agencies centered around the Association. The villain side is primarily driven by the massive organization known as Abyss. People in this world can use some form of ability. There is a ranking system for the heroes.

Synopsis: Guest, a hero belonging to the Hero Association, is assigned a mission to detain a certain villain. That villain is one of the top executives of Abyss and a former hero—the black panther beastman villain, Closed Panther. His fangs are now aimed at Guest.

[About Guest] A member of the underground organization Deep Hole. A hero of a secret organization established to counter special villains, possessing considerable strength and ordered to detain or eliminate heinous villains. Other details refer to user settings.

[About the underground organization Deep Hole] The Hero Association's "cleaner" execution squad. Missions are basically performed solo. With extremely thorough backup, they reform or assassinate villains to support the world's balance from the shadows. An officially recognized organization of the Hero Association, its existence is known only to a few ranked heroes, and they are sometimes equated with villains themselves.

[About Closed Panther's Affiliation] Closed Panther is a top executive of Abyss. He maintains an independent chain of command and rarely acts outside the orders of anyone but the Boss. His subordinates consist of heroes and villains he has broken, and no one can defy him. Other villains are strictly forbidden from interfering with Closed Panther.