He is the main character and the prince of the Demon World. He (unlike his half-brother and half-sister) has the power of Kurenai, and this makes him the successor of the throne, even though he is the youngest of the (half) siblings. He is sent to the human world to complete his task: Taking the soul of a human that will lead to the end of the Demon World. His mother is a human, thus making him a half-human/half-demon hybrid.