Based on the doujin CG by Ibukichi.

Bunta is a 43-year-old man who does nothing but think about his hot teacher from Nakajima Nanoka high school with whom he had a secret relationship. After years, she accidentally meets a woman who looks a lot like her old teacher named Nakajima Kanoko that she is a high school teacher with the same surname. Bunta falls madly in love with Kanoko and does not want to wait until the latter disappears like her former teacher.