A Rochester, New York synagogue and Hebrew School is the setting for the coming of age/coming-out dramedy “Tahara.”

Teenage girls Carrie (Madeline Grey DeFeece) and Hannah (Rachel Sennott) prattle on about crushes, sexual experiences and desires, tactlessly commenting on the day’s ceremonies, traditions and participants the way self-absorbed teenaged girls do.

But the film’s title should tell you just how inappropriate and heartless this is, in a “today of all days” sense. The synagogue is filled with teens. One of their classmates has died. Samantha took her own life.

Olivia Peace’s film, based on a Jess Zeidman script, is aggressively transgressive, sometimes hilarious and occasionally even tender. But not over the dead girl, who apparently wasn’t popular and lived under a sort of mean girl shunning isolation.

So when teacher Morah Klein (Bernadette Quigley) takes the kids into a classroom for some formalized (pre-printed handouts) “grief counseling,” and lectures that “as the Babylonian Talmud tells us, all Jews are responsible for each other,” it kind of falls on deaf ears. And not just because Ms. Klein has the bedside manner of a militant West Bank settler (she boasts about service “fighting for Is-RYE-el”).

In this insular world, teens will be teens. “Performative” grief runs up against eye-rolling narcissism. I mean, who has time for self-reflection?

That’s just the backdrop for the day-long conversations/confessions of Cassie and Hannah. Their banter ranges from who’s had a nose job to comparing their near-sexual experiences to crushes and talking dirty about their high school chemistry teacher. “Would you ever kill yourself?” even comes up.

Yes, they’ve been friends forever. So Hannah has license to go on and on and on about her lust for tall classmate Tristan (Daniel Taveras) and Cassie is obligated to listen, or pass notes back and forth right in the middle of the service.

Sennott, of the even-more outrageously sexual Jewish funeral comedy “Shiva Baby,” is as “out there” as ever, giving us real in-the-moment teen plotting and fantasizing and stumbling like the clumsy, thoughtless she’s playing. DeFeece (of TV’s “Blue Bloods”) is the reactor here, subtle enough in getting across the more-guarded and sensitive Cassie’s differences from horny Hannah.

She listens and indulges her friend, takes in everybody else’s reactions and identifies with any peer with the temerity to admit, “Today I feel so fake.”

But when Hannah stops prattling and playing with her zits in the mirror long enough to wonder if she’s a good kisser, the two swap spit to compare notes. And whatever self-assessment Hannah assigns her skills, Cassie’s world is rocked to the core.

Queer filmmaker Peace uses drawn or stop-motion clay animation to illustrate the erotic delights and flights of fancy the girls experience in their dreams — Hannah’s lust for Tristan — or the moment — Cassie’s hormonal eruption at locking lips with someone she wishes was more than just a friend.

There are laughs in the awkward ways Cassie tries to get a repeat performance, and universally recognized winces of recognition as we fear for her feelings about where all this is going. Sennott has mastered this sexually ravenous young woman “type,” and effortlessly finds the laughs built into her character. But DeFeece makes the most of every close-up, wringing pathos and laugh-at-her-pain longing out of scene after scene of this talky but mercifully brief day-I-came-out tale.

Peace shot the film in a cellphone-friendly 1:1 aspect ratio, which balloons out to Academy 1.37:1 to underscore the moment Cassie’s world opens up.

The boxy look doesn’t add to the movie, and feels like a young filmmaker’s semi-misguided “experiment” when whispered or note-passing scenes require subtitles. That creates technical issues rendering the titles into tiny fine print and emphasizes the movie’s unpolished indie pedigree.

But Peace and the cast create an amusingly complete “world,” with the class’s biggest cynic also its most passionate vaper/poseur (Shlomit Azoulay), the performative weepers and even a couple (Keith Weiss, Rachel Wender) bickering over a cell phone video that “proves” the Earth is flat.

And short conversations or long, tasteless or touching, DeFeece and Sennott make their conversations a fascinating hour of teen eavesdropping — repellant, ridiculous and risible all at once.

Rating: unrated, profanity, teen smoking

Cast: Madeline Grey DeFeece, Rachel Sennott, Daniel Taveras, Shlomit Azoulay, Keith Weiss, Rachel Wender and Bernadette Quigley

Credits: Directed by Olivia Peace, scripted by Jess Zeidman. A Film Movement release.

Running time: 1:18