After accidentally discovering a gonzo video of his father and stepmother having sex, the son develops uncontrollable lust toward his stepmother. To fulfill his desire, he contacts GOS for help. His stepmother, introduced as a monitor for a newly opened massage parlor, arrives without suspicion and lies down on the treatment table. Gradually losing control, she writhes her hips while blindfolded and restrained, her body further stimulated by talcum powder. Unaware that her assistant is actually her son, she's caressed by four hands and reaches climax trembling. The son's penis penetrates her, and as she writhes in pleasure, she screams, "The massage feels so good!" Without realizing their identities, she experiences both her son and staff member's cocks, ultimately reaching ultimate ecstasy.