Hibiki is a married woman living with her husband and her stepson. She shares a loving relationship with her husband, enjoying passionate creampie sex at night, and their marriage is harmonious. However, whenever her husband goes to work, Hibiki is forced to wear a collar and trained like a pet by her stepson. She's made to spread her pussy and masturbate on command, and even under the dining table—while her husband sits right there—she's tormented with a remote-controlled vibrator. Subjected to brutal deep throat sessions and forced to take cum in her mouth, Hibiki is gradually broken in. Eventually, her body and mind become completely dominated by her stepson's huge cock and rough sex, until she sinks to the level of a bitch in heat, panting, "My pussy feels so good!"