Rena, a daughter-in-law, is relieved that her sudden cohabitation with her father-in-law, Ginji, is going smoothly. Meanwhile, Ginji, who senses that she is not satisfied with her indifferent husband, Akio, gives Rena a massage under the pretext of treating her muscle pain from her recent early morning jogging... Rena readily accepts the request, but Ginji takes the opportunity to attack her sensitive parts. Rena begins to feel her body heat up and tries to resist, but it is already too late. Ginji, who has lost all sense of reason, devours her voluptuous and seductive body like a beast...