King Enma Jr., commonly known as Koenma ("little Enma"), is the son of Enma, the ruler of the spirit realm, referred to as "Yama" in the English anime. Koenma appoints Yusuke Urameshi as the spirit detective. His Japanese voice actor is Mayumi Tanaka, and his English voice is provided by Sean Teague in the Funimation dub. In the first movie, "The Golden Seal," he is voiced by Brianne Siddall, and in the second movie, "Bonds of Fire," by Eric Stuart. Koenma's name combines his father's name (Enma) with "Ko," meaning "child" in Japanese.
Koenma initially appears as a toddler, though he is over 700 years old and possesses vast knowledge of the universe. He serves as comic relief, often portrayed as cowardly. However, if Yusuke or his friends are in danger, Koenma will offer all the help he can. He is generally seen as a good leader and a nice person. His role in the Spirit World involves deciding who goes to Heaven and who goes to Hell, a responsibility usually attributed to his father, King Enma, who is frequently away on business trips.
Koenma has the ability to transform into his teenage form, fearing ridicule from Yusuke and Kuwabara. He has a "Jr." symbol on his forehead and carries a pacifier that stores his spiritual energy. When released, this energy creates the Mafukkan, the most powerful defensive spell in the Spirit World. Depending on the amount of energy stored, Koenma can seal demons of various strengths. By the time of the Chapter Black Saga, he can easily seal an S-class apparition.
Koenma is responsible for the Spirit Detectives, a position he requested. When Shinobu Sensui attempts to merge the human and demon worlds, Koenma feels responsible for him. During his confrontation with Sensui, Koenma uses the Mafukkan, willing to suffer alongside Sensui as atonement. Koenma betrays his father by siding with Yusuke after the Spirit Defense Force wants to kill Yusuke for being a Mazoku. Consequently, Koenma briefly lives in the human world, fearing his father's wrath, before returning to the Spirit World. In the manga, Koenma overthrows Enma after discovering that Enma deliberately allowed demons into the human world to create conflict.
