When his wife goes on a trip away from home, she asks her mother to look after her husband, Ataru, and his mother-in-law, Erika, comes to visit. However, Ataru is unable to welcome her. To Ataru, Erika, who has a bewitching charm, is not just a mother-in-law, but a woman in her own right. Until now, Ataru has desperately tried to suppress and hide his lust for Erika. Now he lives under the same roof as his mother-in-law. Moreover, it is a perfect situation, with his wife not around. Finally, Ataru's patience reaches its limit...