Mofuku kyôshi: Nodo no okumade (1997)

Misako, dressed in black, sits on a chair at the podium and monitors her students' tests. Her husband, Shinichi, who is also a teacher, had just died the other day, but she had come to school to take an important exam for the third-year class he was teaching. When the test was over, she sat in a daze in front of her husband's portrait. The things that came back to her mind were the acts of love she had made with her husband. The days of her youth when she gave deep throating to Shinichi, her high school homeroom teacher. And the many passionate sex experiences they had after they got married. While thinking about these things, Misako puts her hand under the hem of her kimono...