Koenma is a major supporting character in Yu Yu Hakusho and the son of King Enma, ruler of the Spirit World. He serves as the young-looking bureaucratic authority who assigns Yusuke Urameshi his missions as a Spirit Detective. Though he appears childish, Koenma is intelligent, responsible, and often serious about his duties. He guides the heroes, manages Spirit World affairs, and provides crucial information and support throughout the series. His role is both comedic and administrative, balancing authority with a surprisingly human personality.