One day, Shohei's father brought a young and beautiful woman. Her name is Sanae. Ultimately, Sanae and Shohei are related, and she becomes Shohei's mother. Shohei lost his mother at a young age so he never got used to life with a woman in the house. It's also a life together with Shohei and a beautiful woman whose age hasn't changed much. The stimulation was too strong for Shohei. And that day will come. Shohei could not control his sexual desire and committed a crime with Sana.