When Eriko was a student, she was in love with her childhood friend Kyo. However, one day on the day of their date, Kyo disappeared. After that, Eriko married Kyo's best friend, Takeshi. Eriko, Kyo, and Takeshi were in a love triangle when they were students. Then, when they met again for the first time in 20 years, the gears that had stopped moving between Kyo and Eriko started to move again... Her feelings for her beloved husband haven't changed, but she hasn't forgotten her feelings for Kyo. Although she is tormented by guilt, a messy love triangle full of immorality begins again...