One day, Shohei's father brought with him a beautiful young woman. The name is Sanae. In the end, Sanae and Shohei had the same last name and became Shohei's mother. As for Shohei, who lost his mother at a young age, he has never been used to living with a woman in the house. It is also the life together of Shohei and a beautiful woman who is not too far apart in age. The stimulation was too strong for Shohei. And that day will come. Shohei cannot control his sexual desires and rapes Sanae.