The quinceañera is a stately Hispanic rite. All the giddy femininity of a debutante debut, all the ritual of a Latin bat mitzvah. Uncomfortably done-up teens dance careful waltzes and the 15 year-old girl — now, officially, a woman — is presented to the community with solemn religious oaths. And as soon as that’s over, the DJ starts thumping the reggaeton, frumpy old aunts unloose serial tequila shots and the virginal quinceañerita and all her budding friends begin pantomiming rude sex on the portable dance floor.

This is the first scene of the Sundance-lauded Quinceañera. It rings with the exuberant authenticity writers / directors Richard Glatzer and Wash Westmoreland want for the entire film. Realism was the goal. Specifically, they set out to reinvent the Kitchen Sink realism of postwar British cinema — a genre of gritty, working-class drama, frank sex, and bubbling political commentary set amidst the industrial blightscapes of northern England — with a coming-of-age story in L.A.’s Meso-American Echo Park neighborhood.

The first quinceañera belongs to Eileen. The story belongs to her cousin, Magdalena (Emily Rios) who’s skulking around the party’s corners. Her own celebration is impending, but, teen woe, she’s going to have to wear her cousin’s hand-me-down dress and her father, religious and tradition-bound, won’t spring for the Hummer limo.

Soon come bigger problems: A fumbling session in the park with striving boyfriend Herman (J. R. Cruz) and she’s pregnant. Magdalena insists she’s still a virgin. Skeptical dad sends her to live in exile with her elderly bachelor uncle Tomas (Chalo Gonzalez) and the family’s other black sheep: thuggish cousin Carlos (Jesse Garcia). The odd trio’s new landlords are a couple of gay gringos relocated from Hollywood, the vanguard of gentrification.

Quinceañera makes inspired use of a largely amateur cast. Rios, 16, had never acted on camera before taking the role. Her subdued and uncertain delivery gels perfectly with teen boredom and bewilderment. Garcia has a longer resume, but the same effect.

Thus the engine that could power audiences across the suspension bridge of disbelief revs up. But the movie doesn’t budge. Shot entirely in Echo Park, with residents as extras and their living rooms as soundstages, the listless camera still can’t manage much enthusiasm for the visual nooks and crannies of the community it’s supposedly celebrating.

In spite of the film’s quietly revealing language — adults in subtitled Spanish, teens in nearly unaccented English — the dialog is uneven; in parts distractingly atrocious. Magdalena’s mother earnestly asks her daughter if she’s “having relations.”

Ultimately, Quinceañera wants to be a gritty story of unconditional love changing a tough place. Only the movie’s Echo Park is not a tough place. Money isn’t a crushing issue for any of the characters. Nor crime. Nor drugs. Parents, if misguided, are present and well-intentioned. Magdalena’s friends chatter vapidly, go to school, and take the bus to whitest Glendale to hang out at the mall.

Herman abandons Magdalena, as she continues to insist she’s a virgin. Somewhere around here the story abandons her too, then latches onto Carlos and floats away. It turns out Carlos, a set-piece cholo with blue flannel shirts and menacing tattoos, is more-or-less openly gay and becomes the plaything of his new landlords.

Wash Westmoreland — writer/director of the cult-hit gay porn reverie The Fluffer — has his hand firmly on the camera here. His cut of the trio’s tryst is oddly lurid and dissonant. Carlos’ deepening involvement with the men has the feel of a sexual fantasy. Like all fantasies, this one (aside from a bit of racial nuance) has no obvious point beside itself and in going nowhere, totals a good character’s credibility. An obviously gay gang member? And one who, when his boyfriends toss him aside (and evict him, his beloved uncle, and his pregnant cousin) is so full of rage that he — start dialing 911 — lightly vandalizes their car?

Quietly the trio of castaways becomes a loving, supporting family just as their world starts to fall in on them. Improbable circumstance and predictable circumstance join forces to save the day.

Quinceañera is bookended by Magdalena’s by-now-pretty-well-forgotten-about quinceañera. Most of what falls between the bookends is fluff. Uplifting fluff, but fluff that if it weren’t wrapped in a tortilla, would have only made it as far as a Lifetime movie of the week. Glatzer and Westmoreland’s story of rejection, love and growth is certainly a plausible account of life in Echo Park. At no point, though, does Quinceañera feel like the story of the neighborhood.

When Magdalena’s Hummer limo pulls up to the storefront evangelical church, all the kids inside, all real east L.A. teens, rapidly headed for their own Echo Park rites, spill out. They bend to goofy poses, check their cell phones and flirt. Quinceañera does well using them as background. It just isn’t interested in putting them in the foreground where, for realism’s sake, they belong.

– Louis Wittig is a writer living in New York.