Eri is a single mother living with her dear son Tatsuya. She and Keichi have been in love for a long time but Eri still hid this with Tatsuya, for fear of affecting his upcoming exam. Once accidentally, Tatsuya discovered that Eri and Keichi were fucking each other. Do not want another man to rob the beloved mother, that night Tatsuya sneaked into Eri's room and invaded her! Despite loving Keichi, the brave dick and the straightening into the uterus made Eri feel himself became extremely strange. She gradually became lecherous, desiring sex. "Just one last one, after the mother got married, we could not do this anymore" ...