Enma Daioh, known as Great King Enma, rules Enma World (Enma-kai), a realm linked to the afterlife or supernatural dimensions. His primary duty is judging the deceased, empowered by a potent scepter symbolizing his authority. This scepter becomes central to the series when the protagonist, Ojarumaru, steals it after Enma's ukulele playing lures the young prince into his realm. The theft forces Enma to pursue its recovery, though he seldom intervenes directly in the human world.

Furious over the loss, Enma delegates the retrieval task to his three adopted oni children—Aobei, Akane, and Kisuke—the Oni Child Trio (Kooni Trio). These children, with contrasting personalities and wielding giant cutlery as makeshift weapons, frequently travel to the human world to confront Ojarumaru. Their persistent efforts consistently fail due to Ojarumaru's cleverness or accidental mishaps, cementing Enma's role as a distant antagonist. The trio's ongoing pursuit underscores Enma's unwavering demand for the scepter's return, though his reactions to their failures remain unexplored.

Enma's relationship with the Oni Child Trio is strictly hierarchical; he assigns missions but shares no documented emotional or developmental interactions. Their dynamics lack explicit backstory, and Enma's character does not develop across the series. His influence drives the trio's recurring appearances but does not extend to personal story arcs or deeper exploration of his realm beyond its narrative function.

In spin-offs, movies, and specials, like *Ojarumaru the Movie: The Promised Summer - Ojaru and Semira* or the television special *Heian-chō Onigami Kessen*, Enma's role remains consistent. No additional dimensions—such as expanded motivations, history, or relationships—are introduced. His portrayal stays focused solely on scepter retrieval, without revealing his origins, personality, or significance beyond this plot element.