100 Girls (2000) on Netflix

Plot summary

Matthew is a college freshman who finds himself shut in a dormitory elevator when the power fails. In the dark he has sex with a woman whose face he never sees. Morning comes, the lights return, and he is alone, holding her panties but no name, no description, and no idea which room she came from. The only thing he knows is that she lives in the all-girls dorm known as the Virgin Vault. He takes a job as the building's maintenance man so he can move through its hallways without raising suspicion. Searching the residents, he crosses paths with Patty and her boyfriend Crick, with Wendy, a former high school classmate, and with Cynthia, a girl he is too nervous to speak to.