King Enma is a giant bearded Lord of the Spirit World. He is one of the most powerful characters in the series. He is very strict and short tempered and punishes his son, Koenma, for incompetence at a job that is actually his responsibility.
King Enma is first mentioned in the Spirit Detective arc, when Koenma attempts to retrieve the three Artifacts of Darkness to avoid invoking his world rending and destroying wrath; however, he could not avoid being punished personally by his father, comically portrayed as spanking.
Later in the Chapter Black arc, he orders the death of Yusuke to prevent the destruction of the universe's balance, which he removed as soon as Yusuke had left to the Makai and later proven to not be as violent as he suspected.
In the anime, it is implied that King Enma, had actually been pulling the strings and had his top unit attack Yusuke to awaken his potential to fight Sensui, and his attempts to have him killed were to force the former Spirit Detective to go to the Makai to hone his control over his new powers so he wouldn't be a threat to his friends. He apparently keeps his title and is secretly proud of his son's new independence.
In the manga, Koenma learns his father is corrupt. He brainwashed demons and then let them loose into the Living World in order to stir up trouble and thus add meaning to his existence as a protector against the demons. Koenma dethrones his father and takes over Lordship of the Spirit World. King Enma valued the balance of Reikai, Ningenkai, and Makai, which is why he attempted to kill Yusuke, in order to maintain balance.
Though powerful, even he cowed and submitted to the wishes of the Three Kings of Makai, allowing them the services of Yusuke, Hiei, and Kurama.
- In real life, Enma is a deity belonging to Buddhism and Hindu practice, who is regarded as the fierce lord and judge of the dead, as well as the Mover of Samsara and the upholder of spiritual practice. His origins do not stem from divine sources, but rather that of the world of men. In Hindu lore, Yama was described as the first man who died that followed the path of enlightenment and was granted the position by the gods upon reaching heaven. In Tibetan lore, Enma was a monk that devoted himself fervently to Buddhist practice; on the day which would allow him enlightenment however, a criminal trespassed into the cave where he practiced and murdered him. Angered and with fury, Enma returned as a violent entity and slew his aggressor, but rampaged all across the land. The wrathful entity Yamantaka, or Daitoku-Myoo, halted him by showcasing a visage that instilled into him fear of death and that which he had inflicted on others; after this, he was allowed to judge the dead until the day when the cycle of Samsara would be ceased no more due to his merits and atrocities.
- King Enma's appearance is vastly different from his son's view on him in episode 6 and his actual appearance in the Chapter Black arc, which is portrayed as a stereotypical, beastly version of King Enma, and which is proven wrong when he appears to be a large yet normal version of King Enma with glasses.
- During the Chapter Black Saga, Sensui states that the A Class have powers equivalent to gods of various reilgions and myths. This implies that King Enma is likely a middle or upper A Class.
- King Enma shares similarities to King Yemma from Dragon Ball Z in both appearance and occupation. This would be due to both being based on the same deity.
- In YuYu Hakusho the Movie: Poltergeist Report, It was stated that King Enma defeated Yakumo thousands of years before the start of the series. It is later revealed that King Enma could not handle the power of Yakumo's Power Sphere, resorting to the use of a Reikai seal (similar to the Kekkai and Mafuukan used to seal away the strongest S class powers) to seal away the Power Sphere instead. This demoted Yakumo from an S class threat to an A class threat, allowing King Enma to finally defeat Yakumo.