Oni (鬼), translated as "demon", "devil" or "ogre", can be referring to one of the following topics below.
- The early tentative title of Nioh.
- The official codified term for the monstrosities within the Toukiden games.
- The "dark" energies and entities in the Fengshen Yanyi series.
- A member of a mystical race in the Harukanaru Toki no Naka de series.
Oni is also the kanji character used in the legendary epithets for Sengoku Jidai figures like Yoshihiro Shimazu, Katsuie Shibata, and Hanzō Hattori.