"The Girl Next Door" owes a great deal to 1983’s "Risky Business," starring Tom Cruise and Rebecca DeMornay, a cinematic cousin that people are still talking about 21 years later. "The Girl Next Door" more than likely won’t achieve the iconoclastic status that "Risky Business" has, but it’s harmless enough to qualify as popcorn fare for mature teens.

A vivid daydreamer, Matthew Kidman (Emile Hirsch, "The Emperor’s Club") is also an ambitious high school senior, with a real shot at winning a scholarship to attend Georgetown, and he has serious political aspirations. Life gets even better when Danielle (Elisha Cuthbert, formerly of FOX’s "24"), a 19-year-old hottie, moves in next door and they both fall for one another hard. Matthew is on Cloud Nine and the whole world is his oyster, then the inevitable twist threatens to screw up everything. His dream girl is a recently retired porn starlet and his future is put into jeopardy when the resulting chaos rears its ugly head. To quote the film’s central quandary, "Is the juice worth the squeeze?"

In town to housesit for her aunt, Danielle is paid a visit by a former boyfriend, Kelly (Timothy Olyphant, "Go"), an adult film producer trying to persuade her to make a return to porn. She reluctantly agrees even against Matthew’s and her own wishes. When Kelly learns of Danielle and Matthew’s growing romance, he takes Matthew, who has lived a rather sheltered existence, under his wing. Treated like a social outcast at high school by the popular crowd, especially by the jocks, Matthew is schooled by surrogate big brother Kelly on the finer points of earning respect from one’s peers. Rule number one: "Always leave ‘em wanting more."

But their friendship takes a turn when Matthew, assisted by his best friends Klitz (Paul Dano, "L.I.E.") and Eli (Chris Marquette, CBS’ "Joan of Arcadia"), follow Danielle and Kelly to a porn star convention in Las Vegas to convince her to permanently leave the porn world. An enraged Kelly retaliates against him; triggering a series of betrayals and wild schemes that test Matthew and Danielle’s bond.

The main problem with the film is the excess of its second half; it doesn’t know when to quit with the plot mechanics. The girlfriend as porn star angle would be enough to sustain most films, but here we also get bombarded with subplots involving blackmail, robbery, going to the senior prom, and making a racy video in the most unexpected of places. Director Luke Greenfield frames all of the action in a music video format that partly works but mostly underlines the lack of story cohesion.

Hirsch and Cuthbert both equate themselves well enough, but the wildly charismatic performances given by Olyphant and James Remar ("48 Hours") as duplicitous porn world insiders are the film’s saving graces — they rise above the material and elevate the film.