During his childhood, Ryuuhei Oda watched his affectionate older brother die, leaving behind a strange symbol beside the body. Now in his second year of high school, the spirited and spontaneous teenager devotes each day to his favorite sport—kickboxing. One evening while returning home, a bizarre creature gnaws at Ryuuhei"s leg, sending him into an uncanny dream populated by peculiar beings. The following day the same monsters attack in reality, and Jessica Clayborn with Aruto Fushibe intervene, insisting that Ryuuhei has become their newest ally. Confronted by an urgent danger, Jessica compels the bewildered Ryuuhei to assume the role of a "knocker‑up," someone capable of facing nightmares that spill into the waking world. Leveraging his kickboxing prowess, Ryuuhei unlocks his latent abilities to protect the city, only to encounter a familiar mark—one he can never shake.
