While her husband was away on business, Hisae made a mistake with her only son, Kenta. After her husband's business trip ends, the three of them start living together as a family. With the father at home, the mother and son refrain from having sex... However, as the mother and son become more and more sexually frustrated, they gradually can't hold back. When the father is not around, the mother and son continue their relationship secretly... And the moment the father goes out, the mother and son begin to desire each other intensely!! Before the father comes home, the mother and son engage in a fierce mating, trying to reach climax!!