Father and son... A tree who has been married as a second wife to a family of only men. "Such a beautiful person is my mother..." A son who can only think of Itsuki as a woman, not as a mother, because they are not related by blood. Days of masturbation imagining Itsuki's nakedness... One day, a terrible incident hits such a mother and son. The son-in-law deepens his affection for Itsuki's actions to protect his son-in-law with his own body. With that as an opportunity, the forbidden love between Itsuki and his son...
