Oni are often featured in Japanese mythology as creatures that torment humans, cause disasters, or act as enforcers of hell’s punishments. In many tales, they devour humans or spirits, and their appearance is meant to inspire terror. However, in certain Buddhist traditions, Oni are also seen as guardians or protectors of sacred places, keeping out evil forces.

The portrayal of Oni varies in different stories—some can be purely malicious, while others have a more complex role, acting as both punisher and protector, reminding people of the balance between good and evil.

Oni are also central to Japanese festivals such as Setsubun, where people throw beans at an Oni mask or effigy to symbolically drive away bad luck and evil spirits. The Oni has become a lasting symbol in Japanese culture, representing the boundary between chaos and order, good and evil.