The Torture Onanie (1991)

Original title: ザ・拷問ONANIE

An excellent female college student attending the university's medical school. She developed a mutual liking for a boy who was a classmate of hers at university, and they started dating, but it never developed into a physical relationship. This is because she once had a tragic experience of being raped, which left her traumatized and her mind refusing to have healthy sex with a man. But she also has sexual desire. She had no choice but to drown out her rising desire as a woman through masturbation. Moreover, for some reason, the side dish of that masturbation was always the same image of her as she was being raped. Then, one day, a man appears who can see through her desires, breaks the spell of her trauma, and begins to train her in SM...