The four friends in American Pie are Jim Levenstein, played by Jason Biggs, Kevin Meyers, played by Thomas Ian Nicholas, Oz Ostreicher, played by Chris Klein, and Paul Finch, played by Eddie Kaye Thomas. They are all high school seniors and are feeling the pressure to lose their virginity before they graduate.
Jim is particularly desperate to lose his virginity and becomes infatuated with a foreign exchange student named Nadia, played by Shannon Elizabeth. He enlists the help of his friends to set up a webcam in his room so he can record their encounter. However, things go wrong when Jim's dad accidentally sees the video.
Kevin is in a long-term relationship with his girlfriend, Vicky, played by Tara Reid, but they haven't had sex yet. He tries to convince her to have sex with him, but she wants to wait until they are both ready.
Oz joins the school's choir in an attempt to meet girls and ends up falling in love with Heather, played by Mena Suvari. However, he realizes that she is more interested in him as a boyfriend than as a hookup.
Finch, meanwhile, spreads rumors about his sexual exploits to impress his classmates, but it turns out he is just making it all up.
As the prom approaches, the friends become increasingly desperate to lose their virginity. Jim ends up hooking up with Michelle, played by Alyson Hannigan, who turns out to be a band geek with a sexually aggressive personality. Kevin and Vicky have sex on prom night, while Oz and Heather decide to wait. Finch finally admits that he made up the stories about his sexual conquests.
In the end, the friends realize that losing their virginity wasn't as important as they thought it was, and they come to value their relationships with each other and the people they care about.