Don't remember everything perfectly but pretty sure that it starts with a class (of boys?) watching a video on how to properly treat your partner during sex. In the video they see a male (maybe teacher) having sex with a possibly unwilling female (maybe classmate). The video has a voiceover which tells how a man should treat the girl during each step during sex, however the male in the video either somewhat or entirely contradicts the voiceover, as he has really rough sex with the female in the video.
This next bit may be entirely fabricated by my imagination but, after the video ends the male and the female in the video appear in the classroom, after which the female is then is made to have sex with the boys of the classroom.
This next bit may be entirely fabricated by my imagination but, after the video ends the male and the female in the video appear in the classroom, after which the female is then is made to have sex with the boys of the classroom.