A photographer falls in love with a nymphomaniac model. But also his assistant Olga also has kept an eye on him. Soon he has to decide between the two women.

At the girls' school, the young teacher requests the young women to prepare a lecture on the topic "The Preliminaries", for next week, before the year's end. The girls would contact him if they had any problems with their work. Thus a series of sexual experiments start, which will involve the whole class, and even the teacher.