Aubrey Plaza is something of a deadpan genius on TV's "Parks and Recreation," and she showed promise expanding that snarky persona in 2012's "Safety Not Guaranteed," but her deserved breakthrough lead role in "The To Do List" is the first time she's proven she has the range necessary to play different kinds of parts. Her character, recent high school graduate and valedictorian Brandy Klark, is a responsible goody two-shoes who probably wouldn't know sarcasm if it slapped her in the face. Dragged to a kegger by her more fun-loving best friends, Fiona (Alia Shawkat) and Wendy (Sarah Steele), she finds herself getting drunk and having an awkward intimate encounter with the super-hot Rusty Waters (Scott Porter) that abruptly ends as quickly as it starts. Not wanting to head off to Georgetown University in the fall hopelessly inexperienced in the ways of sexual activity, Brandy compiles the title list with the intention of sampling everything. She doesn't want emotions to get in the way of her "research," but doesn't it always?

"The To Do List" is a much raunchier distant cousin to 2010's irresistibly funny and wise Emma Stone-starrer "Easy A," the two films pretty much the only teen sex comedies in memory told from a female's perspective. In this way, it's close to trailblazing—if not specifically in what happens, then certainly in how it happens. Draped in nostalgia—the setting is 1993, full of period-specific soundtrack cuts, costume styles, production design, and pop-culture references—but treated with a welcome restraint in sentiment, writer-director Maggie Carey (making her feature debut) finds a fresh moralistic angle, one that sends out the mature message that, as long as a person is making the choice for him or herself and taking the necessary precautions, sex doesn't have to be the huge, earth-shattering big deal society and the media make it out to be.

Loose and limber, proudly R-rated and wickedly amusing, "The To Do List" goes out on a limb, not always trekking down the most conventional or expected path. Most of the time, Carey is keenly intuitive in balancing outrageous comedy with a John Hughesian sweetness that treats its teenage characters with respect and honesty. On rarer occasions, the material does threaten to wade into smuttier waters (bodily fluids are liberally on display, as is a scene that wades disturbingly into "Pink Flamingos" territory). When the movie isn't trying so hard and simply observing Brandy's summer experiences, from her hangouts with her gal pals, to her eye-opening discovery of masturbation, to her job at the public pool opposite Rusty Waters and the heart-on-his-sleeve guy friend who pines for her, Cameron Mitchell (Johnny Simmons), is when it works best. Scenes where she checks off hand jobs, finger blasting, and dry humping are absurdly funny in the way that the experiences are comically portrayed but far from idealistic. And, in a way, that's the point: things never, or rarely, go the way one imagines them, so there's no use in trying to control how everything happens.

The cast of "The To Do List" is young, but not that young (all of the so-called teens are played by twenty-somethings, but that is neither here nor there). Leading the way is Aubrey Plaza, so immensely watchable as Brandy Klark that the film works first and foremost because she is the one the viewer actively wants to follow. Brandy is overly naïve at times—she guesses that a "pearl necklace" is elegant, and assumes that "motorboating" will be a cinch since her uncle has a boat—but Plaza convincingly creates a clear arc for a character who matures in more ways than one as the dog days of summer approach. Virtually every actor that surrounds her gets their moment in the spotlight, with Connie Britton (2012's "Seeking a Friend for the End of the World") playing one of filmdom's coolest moms and Clark Gregg (2012's "The Avengers"), as Brandy's judge father, cringing at the rest of his family's nonchalant views of sex. Rachel Bilson (2008's "Jumper") is brazenly acerbic yet real as Brandy's engaged college-aged sister Amber. Johnny Simmons (2012's "The Perks of Being a Wallflower") is close to adorable as Cameron, the guy who is hurt to learn Brandy has been using him. Scott Porter (2012's "10 Years") couldn't be any better playing Rusty Waters, a physical embodiment of perfection whose brain never quite developed as successfully as his body. Alia Shawkat (2012's "Ruby Sparks") and Sarah Steele (2004's "Spanglish") play enormously well off of Plaza as girlfriends Fiona and Wendy, though the former's nickname of Brandy, "Pancake," is uttered so many times the viewer may be tempted to tape her mouth shut. And Bill Hader (2011's "Paul"), as unpredictable—and homeless—pool manager Willy, is very good as he rises above an initial caricature and develops an unlikely friendship with Brandy.

"The To Do List" is a grammatically incorrect title in need of a dash; for a perfectionist like Brandy, it's actually a betrayal that she doesn't get this right when she jots down the title in her trapper-keeper. Editorial missteps notwithstanding, the film marries the tones of 2007's raucous "Superbad" and 2011's slice-of-life "The Myth of the American Sleepover" while lavishing upon the proceedings early-'90s references as varied as "Home Improvement," Tracey Gold and Kirk Cameron, pagers, skorts, "Beverly Hills, 90210," and songs from Mazzy Star, 2 Live Crew, House of Love, Gin Blossoms, Tears for Fears, and The Cranberries. Oh, and any film that includes "Beaches" as a major plot point can't be bad. All of the above comes together quite well until the movie's strained last scene, one of those would-be comic tags that pops up to put a punctuation mark on a scene regardless of whether it makes any sense whatsoever. It's a disappointing way to close a teen film that had earned the right to cross the finish line with more dignity than what writer-director Maggie Carey has ultimately provided. If not a new classic of the genre, do credit "The To Do List" for acknowledging that girls think about sex as much as guys, and need not be prudish about the subject, either. It's a more cutting-edge notion than some may think.