Matthew Kidman (Emile Hirsch) is a high school senior who has recently been accepted to university. Hes the student council president and hes raised enough money to give a smart Cambodian kid a new chance in life by bringing him to the school. Matthew is not part of the popular crowd - although he wants to be - but hes a nice guy and, well, hes the typical boy next door.
Strictly speaking, when the gorgeous Danielle (Elisha Cuthbert) moves into the house beside his, shes the girl next door - but not like any that Matthew has ever known. When Danielle catches Matthew spying on him from his window, its the beginning of a relationship that is as unexpected for Danielle as it is for the love struck Matthew. Matthew and his two equally uncool best friends, Eli (Chris Marquette) and Klitz (Paul Dano) cant believe that Danielle actually likes to hang around with Matthew and really seems to like him.
Danielle likes Matthew because of the way he treats her - something she is not used to from the other guys she has known - and Matthew realises why when he discovers that the girl of his dreams is a porn star. The news is a shock and Matthews first reaction is not good.
Soon, however, Matthew wants to save Danielle from her lifestyle - but then her movie producer, Kelly (Timothy Olyphant) comes onto the scene and wants her to do a new flick. Matthew, Eli and Klitz follow Danielle to a Las Vegas Porn Star Convention where Matthew tries to convince her to give up the business. Kelly turns nasty and makes life difficult for Matthew by stealing from him - but the guys come up with a plan to save the day. It involves the school prom where Matthew, Eli and Klitz arrive with some very special dates who have the rest of the guys drooling.