Kanon, a female teacher, lives with her husband and his younger brother. She also happened to be the assistant teacher of her brother-in-law's class. One day, she receives a request from her brother-in-law, "I want to know a woman's body." It was her bewildered Kanon, but in order to fulfill her brother-in-law's wishes, she gave sex education with her own body as her older sister and her teacher. But one day her sex education becomes incest SEX ….
