Confinement Sister Teachers(kankin shimai kyoushi)

Akiko has just become a teacher in a high school. She teaches the same school as what her elder sister does. Akiko lives with her elder sister and her brother-in-law Norio. Akiko has an affair with Norio, although she knows that it should not be happened. She just cannot stop loving Norio. Until one day, she is visiting her student’s home, some incredible things happened…