Tara (Mia McKenna-Bruce), the gutsy little-girl-lost at the center of “How to Have Sex,” can check most of those boxes. As the movie opens, she and her best mates Skye (Lara Peake) and Em (Enva Lewis) have just taken their college entry exams and have landed in Crete, where they intend to indulge in some competitive drinking and sexual exploits; they converge on their hotel with shrieking excitement that seems girlish one minute and terrifying the next. The petite, baby-faced Tara looks like the little sister of the group, but she turns out to be the brassiest and smoothest talker: Right off the bat, she chats her way to a room with a view of the hotel’s penis-shaped pool.

But it turns out Tara’s bravado is masking the most salient fact of the trip for her: She’s a virgin, and the chief aim of this excursion is to rectify that situation. Walker, the gifted director of photography behind last year’s charmer “Scrapper,” films Tara’s adventure — which takes her from throbbing nightclubs and improbably chilly beaches to hotel-patio hangovers — with sweaty, immersive immediacy, including encounters with a fellow tourist named Paddy (Samuel Bottomley), whose intentions are anything but noble.

In its frankness and often frightening candor, “How to Have Sex” is of a piece with coming-of-age dramas like “Thirteen” and “The Diary of a Teenage Girl,” with a dash of the lascivious, neon-colored bacchanalia of “Spring Breakers” thrown in for good measure. The most appalling set piece of the movie, when a couple of erstwhile tummlers lead a horde of drunken students in a series of sex games, is reportedly based on Walker’s real-life experience in Spain, where she watched sex acts onstage. The libertine antics in “How to Have Sex” aren’t celebrated, but nor are they prudishly judged: Through Tara’s eyes — and ears, when Walker drops out the sound to emphasize Tara’s isolation — we can feel Walker’s own combination of compassionate curiosity and deep misgivings.

The direction and performances in “How to Have Sex” are so spontaneous and naturalistic that the film often plays like a slice-of-life documentary; it’s not necessarily a fully realized story, but as one chapter, it’s extraordinarily vivid. McKenna-Bruce holds the screen with a performance that’s as mercurial as her character, who embodies Britney-like not-yet-a-woman energy with a convincing combination of naiveté and knowingness.

It can’t be said that “How to Have Sex” gives viewers a happy ending, exactly — its hedonistic pleasures come with too much wreckage and desolation for that. But there’s something cheering about it, especially when it comes to Tara’s mum, whom we never meet, but who is waiting back in England for her girl to come home. That fact, and Tara’s own sense of resilience, give “How to Have Sex” not just heart, but a teardrop’s worth of hope.

Unrated. At area theaters. Contains suggestive sexuality, profanity, smoking and drug use. 90 minutes.