Great King Enma (閻羅大王, Enma-daiou, lit. "Great King Enma"; sometimes incorrectly romanized as "Yenma" or "Yama"), is the co-ruler and judge of the Spirit World. He currently reigns this realm together with his son, Koenma.
Great 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, short tempered and punishes Koenma, for incompetence at a job that was, until the outcome of the Three Kings Saga, his own responsibility.
Great King Enma is first mentioned in the Spirit Detective Saga, 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 Demon World and later proven to not be as violent as he suspected.
In the anime, it is implied that Great 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 Demon World 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. Having brainwashed demons and then let them loose into the Human World in order to stir up trouble and thus add meaning to his existence as a protector against the demons. Moreover, all of these dealings were to cover up secretly acquiring resources in the living world for the sake of Spirit Worlds prominence. Koenma dethrones his father and takes over Lordship of the Spirit World for some time. Later on, when Koenma set free his father, they both decided to co-rule Spirit World together. Great King Enma valued the balance of Spirit World, Human World, and Demon World, which is why he attempted to kill Yusuke, in order to maintain balance.
- Enma is the Japanese variant of Yama, a Hindu deity who is also prominently featured in Buddhism, and 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.
- Great 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 Great King Enma, and which is proven wrong when he appears to be a large yet normal version of Great 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 Great King Enma is likely a middle or upper A Class.
- Great 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.
- The Indian Yama, Chinese King Yan, Korean Yeom-ra, Vietnamese Diem La and Japanese Enma refer to the same god which is depicted almost identically in all branches of Hinduism and Buddhism. He is the King of the World of Dead and Final Judge. In the Chinese, Korean and Japanese interpretations, this god is the head of his own bureaucracy, which calculates sins and virtues and their consequences as a basis for the final verdict. And we see this bureacratic organization in the office of Koenma.
- In YuYu Hakusho the Movie: Poltergeist Report, it was stated that Great King Enma defeated Yakumo thousands of years before the start of the series. It is later revealed that Great King Enma could not handle the power of Yakumo's Power Sphere, resorting to the use of a Spirit World seal (similar to the Barrier and Mafukan 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 Great King Enma to finally defeat Yakumo.