Contrary to the T-shirt slogan, sometimes finding “your tribe” is just a baby step.

The hard work of figuring out how you fit into it, how much of its practices and dogma you embrace, has just begun.

“This is Not Berlin” is an immersive Mexican drama about being young, creative and not knowing where you belong. Hari Sama’s fourth film is about sexual awakening, drugs, the underground club scene and homosexuality in 1986 World Cup-mad Mexico City.

Unpredictably plotted — no, it’s not your standard issue “coming of age/coming out” gay romance — and subtly acted, it’s an engaging excursion in the “fluid” or “on the spectrum” sexuality as we understand it today, as experienced by a teen 33 years ago.

Carlos (Xabiani Ponce de León) is an electronics and engineering whiz, bored by his private school and not quite settled in, even with his pals.

We meet him in the middle of a slow motion schoolboys’ brawl he is removed from, above it all and refusing to take a swing. His reaction to these high school vs. high school riots is to faint.

His friends, quick as they are to pepper their conversation with gay bashing, don’t make a lot of it. But they could, if they gave it a thought.

Carlos is tall, thin, with girlishly long curly hair and delicate features. His fainting, he insists (in Spanish, with English subtitles), is because “my highly intelligent brain” tells him “these beatings no sense.”

Musical cues about what’s going on in that car he, his best friend Gera (José Antonio Toledano) and several others pile into include Judas Priest’s “Breaking the Law” blasting out of the car stereo and Carlos insisting to Gera, later, that this Ten Years After tune, “I’d Love to Change the World,” is “one of the most kick-ass songs ever!”

Rob Halford, lead singer of Judas Priest, came out some years after the movie is set, and “I’d Love to Change the World” has lyrics about “dykes and fairies.” Subtle.

Carlos tinkers inventing battery powered gadgets — robot dolls and the like — and can fix anything electronic. And he insists the only thing that keeps him from professing his love for Gera’s punk poetess older sister (Ximena Romo, in Chrissie Hynde bangs) is the fact that she’s “my best friend’s sister.”

But when her band (Manifesto) needs its keyboard fixed, that is Carlos and Gera’s entré to the clubs where Rita and her crew party and perform. That rocks our curious hero’s world — gay men dancing and making out, artists debating the boundaries of art and politics, creative folks creating all around him.

And lots of drugs and nudity, to boot.

Nico (Mauro Sanchez Navarro), their ring leader, takes an interest in Carlos even as Gera is worried about the stigma of “gay nightclub” following them back to school.

As his widowed mother (Marina de Tavira) has crawled into a bottle (booze and prescription pills), Carlos is free to explore this world, with or without Gera or Rita’s help.

“This is Not Berlin” — the title comes from an art dealer’s furious dismissal of art/performance mashup “style” of Nico & Co.  — is about that journey.

While this Hari Sama  (“The Dream of Lu,” “Awakening Dust”) film is no “Y Tu Mamá También,” it features understated performances that capture the figuring-it-out-as-we-go nature of “confused” youth, and an absolutely fascinating milieu.

Carlos may crank out toys and stage effects for Manifesto as his ticket in, but soon he’s swept up in orgiastic body painting “happenings” shot on grainy video for other, bigger works to come.

Rita and Nico and Maud (Klaudia Garcia), who supervises the makeover/transformation that we and his classmates see in Carlos’s hair, makeup, etc., are political because they absolutely have to be.

“They’re KILLING us!” is a frequent refrain of their protest pieces. A couple of those are dazzling stunts that would stop traffic and make headlines, even today.

Sama plays Carlos’s “cool” uncle, guiding his engineering enterprise, riding a motorbike and giving the kid his first joint. As a co-writer/director, Sama gives Carlos’s coming of age not so much a burning-the-candle-as-both-ends urgency as a thirsty curiosity. Carlos is lapping up everything around him like a kid finding a new candy store.

The film’s third act surprises are fascinating post Golden Age of Queer Cinema choices.

No, this may NOT be “Berlin,” legendary for its sexual, artistic and cinematic “freedom” at various times in its history. But “This is Not Berlin” bracingly suggests that the same searching and exploring was going on in places far afield from the city that inspired Christopher Isherwood and later, “Cabaret.” The young people of 1980s Catholic Mexico City, like the post-Franco Spain of Pedro Almodóvar, had their own run of making up for lost time.

MPAA Rating: violence, drug abuse, alcohol abuse, nudity

Cast: Xabiani Ponce de León, José Antonion Toledano, Klaudia Garcia, Ximena Romo, Maura Sanchez Navarro

Credits: Directed by Hari Sama, script by Rodrigo Ordoñez, Max Zunino and Hari Sama. A Samuel Goldwyn release.

Running time: 1:52