Red Classroom is a masterpiece from Chusei Sone, Nikkatsu's star in-house director in the early days of romanporno (romantic pornography). It is also one of the most morally disturbing and ambiguous examples of the genre.

Muraki, a publisher of a small erotic publication, becomes obsessed by an actress in a hard-core underground porn movie that involves multiple rape. He determines to track her down.

When he finally finds her, Nami, now a young woman, tells him that the rape was real. It has continued to haunt her existence. This film, with its restless camera, explores the twists and turns of their relationship subsequent to this revelation, culminating in a mire of total degradation.