A baby named Jiro is left in the care of his foster parents by a formidable oni, promising to return for him in 15 years. As the deadline approaches, Jiro finds himself entangled in a battle against enemy oni, malevolent cultists, and their followers, all while striving to safeguard his loved ones from harm. His odyssey leads him through time, space, and alternate realms, unveiling his true identity as the reincarnation of Shuten Doji.