High school student Kei Nagai is killed in a traffic accident, but immediately revives to learn that he may not be a human after all. Instead, he may be a Demi-Human, a mysterious and almost immortal being blessed with amazing super-human abilities. Scared, he runs away and is aided in his escape by his friend Kai. Unfortunately for Kei, the manhunt is on, and he will soon be caught up in a conflict between mankind and the other Demi-Humans as they prepare to fight for global supremacy.