The story begins in the Japanese Warring States Period more than 400 years ago. Kagero (voiced by Kotono Mitsuishi) teleported his son Rei (voiced by Hirosuke Okano) to the present, and his half-brother Hongli (voiced by Ryotaro Okiayu) traveled through time and space with Rei. After that, Kagero, who was cursed, has been looking for his child. Today, Rei is a 16-year-old high school student. The only difference is that he can ignite a flame from the palm of his hand without being burned. By chance, Rei met a girl named Sago Shimoyanagi (voiced by Yuki Masuda). Like Rei, she is different from ordinary people. She has the superpower of healing wounds. In this way, Rei became a ninja loyal to Liu, which made Fuko Kirisawa (voiced by Akiko Hiramatsu), who has always liked Rei, very unhappy. Fuko's dark emotions made her a puppet of the shadow mage and stood on the opposite side of Rei.