Katsuhiko, the man who shouldered the debts of his parents' family, and Yuko Yajima, who was forced to remarry his wife. Katsuhiko, who acts like a tyrant, treats his sons Makoto and Yuko like slaves. Katsuhiko comes home drunk and takes Yuko. Makoto peeks at the sexual acts of such parents. "I want to protect my mother-in-law ..." A mother-in-law and son who gradually communicate with each other and increase intimacy. However... one day, when Makoto comes home from cram school, he finds unfamiliar men's shoes...