After losing her husband, Reika lived with her son Naoto. However, when Naoto grew up, she decided to remarry to start a second life. On the other hand, Naoto couldn't accept his mother's sudden remarriage and was rebelling against it... One day, Naoto accidentally witnessed his mother being inseminated by her new husband. Naoto involuntarily held his breath at Reika's blissful expression, but he didn't know then that Reika was captivated by the allure of insemination...
