starstarstarstar-outline(3 stars)

At first blush, the teen ride-along comedy “Plan B” feels like it’s following in the libidinous, boozy footsteps of “Superbad” and “Booksmart.” But there’s more going on in here than just hooking up.

Indeed, a hookup is the inciting incident in this raunchy, observantly funny satire, wherein a straight-A student named Sunny (Kuhoo Verma) has sex for the first time at a party she throws while her overbearing mom is out of town. Afraid that the condom she used didn’t do its job, Sunny enlists her best friend Lupe (Victoria Moroles) to track down a morning-after birth control pill.

Easy enough, right? But Sunny and Lupe live in South Dakota, where a moralistic pharmacist refuses to sell them the medication under the state’s “conscience clause,” and the nearest Planned Parenthood is three hours away. One year ago, writer-director Eliza Hittman turned a similar situation into the tense, intimately observed drama “Never, Rarely, Sometimes, Always,” about young women navigating a sexist and patriarchal system to receive basic medical care. In “Plan B,” writers Josh Levy and Prathi Srinivasan deliver the same outraged message with laughs, losing nothing in the translation.

“Plan B” is a genre picture, chronicling a crazy night in the life of two impulsive, foul-mouthed, fundamentally decent kids; Sunny and Lupe encounter a kooky cast of characters on their journey and, happily, manage to encounter their respective crushes along the way. “Plan B” possesses the requisite number of outré sight gags and gross-out humor to qualify it as a sophomoric teen flick. But director Natalie Morales keeps the action running smoothly, allowing her two gifted stars to deliver genuine breakout performances in vivid roles: As the vaping, bad-girl Lupe to Sunny’s earnest overachiever, Moroles combines knowingness and inner sweetness. Verma is just as skillful in giving Sunny layers under her perfectionist exterior. Together, they give “Plan B” the kind of easygoing spontaneity that the genre demands, elevating a fun high school comedy into a genuinely moving testament to sisterhood, abiding friendship and unconditional love.

TV-MA. Available on Hulu. Contains coarse language, sexuality, teen alcohol and drug use and brief nudity. 108 minutes.