The Demon Kai (魔界王 Makaiō, lit. "King of the Demon World") are entities who exist in the Demon Realm.
The Demon Kais were first introduced in the second Dragon Ball: Super Exciting Guide, which was released in 2009.
Occasionally, Core Person with evil hearts are born, the evil Core Person fall under the Demon Kai.
- Shula, Dabura, and Mira have been referred to as kings of the Demon World while Fu was seen as a potential successor to his genetic father and uncle, though are never directly addressed as Demon Kai.
- Additionally. Mirayo in Dragon Ball Fusions is referred to as queen of the Demon World, though it is unknown if she is a female Demon Kai.