Kenichi, the only son, is forced to accompany his father and his father's new bride on their honeymoon. Harboring deep resentment toward his stepmother, Mitsuki, and his real father who drove his mother away, Kenichi grows furious watching his father ignore him while openly flirting with Mitsuki. In a burst of rage, Kenichi forcefully subjugates his stepmother. Initially resisting, Mitsuki gradually submits—whether because her hidden masochistic desires were awakened, or because of the twisted bond forming between them. Ultimately, she obeys her stepson's commands, transforming into a compliant beast. The story unfolds with intense drama, drawing readers into the evolving, perverse relationship between the two.