During the Edo period, a young Jinta and his sister are forced to flee their home, seeking shelter in a mountain village. Years later, Jinta has become a proficient swordsman, dedicated to guarding the village shrine's priestess. Tasked with killing a demon that endangers the shrine, Jinta faces the evil entity in the woods, only to uncover a startling revelation. The demon speaks of events one hundred and seventy years in the future, when Jinta will have to confront the demon again. This marks the start of an epic fantasy adventure spanning several eras, as Jinta pursues a demon through time and must reconcile with his own dark nature.