Married warriors Orin and Genta storm Shutenkaku Castle to destroy the oni lord Shutendoji, who holds their children hostage and threatens Kyoto. Shutendoji kills Genta and their captured daughter before Orin can reach them. Orin offers herself to Shutendoji to spare the remaining child. He agrees — and secretly places twin curses on the child: a two-year lifespan, and the inability to have children with a mortal. The gods respond by blessing the child with immediate adulthood and the right to have children with gods. With Hiruko Taishoten joining them in human form, the family fights Shutendoji across Japan. The final assault on the castle succeeds, and the revelation follows: Shutendoji is the cursed form of Kitsuto, Hiruko's twin brother, born of a human-goddess union and imprisoned to contain an earlier rampage. The family's last battle requires killing Kitsuto while he is merged with Orin; Orin regains her divine form afterward and takes Kitsuto — reborn as an infant — to heaven. The curse is lifted.