It's safe to say that an attractive teenage girl looking to expand her sexual repertoire hasn't necessarily taken on the Labors of Hercules. So it would seem necessary for writer-director Maggie Carey to assemble a few pitfalls for protagonist Brandy Klark (Aubrey Plaza) on her route to carnal awakening. But aside from Brandy's aggravating habit of correcting her partners' grammar during foreplay, The To Do List is reluctant to get its hands dirty, resulting in an astonishingly limp sex comedy.

An academic overachiever, recent high-school graduate Brandy is so naive when it comes to baser things that she turns to Merriam-Webster to explain a "shocker," rather than ask her experienced sister (Rachel Bilson) or best friends (Alia Shawkat and Sarah Steele). Refusing to be an embarrassment in bed as a college freshman, she devotes a sordid summer to crossing items off a comprehensive list of explicit acts, which—if all goes according to her carefully orchestrated plan—will culminate with losing her virginity to the older, Adonis-like Rusty (Scott Porter).

Transforming the ribald into something strictly regimented, the checklist initially seems a novel conceit. But it soon proves a hindrance to the film, instilling an episodic structure that hampers Carey's efforts to spin subplots about several supporting characters. Only during a series of tacked-on endings does it become clear that Brandy's repressed father (Clark Gregg), smitten study-buddy (Johnny Simmons) and slacker boss (Bill Hader) were all supposed to have fully developed arcs of their own. There's a "I didn't even know we were going out" level of awkwardness about watching a filmmaker wrapping up story lines you didn't realize existed.

Far more obvious is Carey's belief that her film's 1993 setting (her own high-school graduation year) is inherently hilarious. The art direction verges on oppressive, with outdated bric-a-brac—a Hypercolor T-shirt, for example—constantly taking the place of actual jokes. This distinct sense of nostalgia just doesn't suit a story of new experiences and self-discovery.

While a sex comedy from a feminine perspective seems laudable, The To Do List ultimately proves a lazy, self-involved lover, too busy indulging its own fetishes and desires to tend to the viewers' needs or offer them much gratification.

Critic's Grade: C

SEE IT: The To Do List is rated R. It opens Friday at Eastport, Clackamas.