Jiro Shutendo emerges from a shadowed demonic realm, an infant salvaged by the oni warrior Senki amid clashing supernatural forces. Entrusted to humans Ryuichiro Shiba and Kyoko under a fifteen-year pact, he is renamed “Shutendoji”—transformed from “Drinking Child” to “Heaven Hand Child” to align with societal expectations.

His childhood unveils eerie gifts: a shadow that morphs into Goki, a demonic guardian. At fifteen, Goki’s intervention spares Jiro from a fatal truck collision, exposing his dormant power. This awakening alerts rival oni, who exploit his classmate Miyuki Shiratori—a conflicted romantic interest—to provoke him.

Jiro’s origin entwines a temporal paradox. His biological mother, dwelling in the Dark Demon World, forged the oni to avenge his abduction, unknowingly birthing the cycle that displaced him. Breaking this loop, Jiro voyages through time, confronts his mother’s tormented soul, and frees her from madness, collapsing the demonic realm and its endless conflict.

Allied with heirs of ancient tribes—Yusuke Shiratori (Miyuki’s brother) and Naojiro Oyama, a yakuza scion bound by ancestral oni wars—Jiro battles cults and mechanized foes like Iron Kaiser, a cyborg avenging his father’s downfall. Harnessing energy manipulation, Jiro forges blades of concentrated ki to vanquish towering adversaries.

In the aftermath, Jiro reconciles his human and oni duality, embraced by his adoptive parents. Peace settles as he builds a life with Miyuki, while Goki and Senki depart to forge a new existence elsewhere. The Dark Demon World’s dissolution ends the oni threat, closing the saga of vengeance and rebirth.