Friendships have boundaries and limits. Aristotle wrote of perfect friends in his Ethics, noting that totals must remain low. Sounds much like romance to me: Is the new bff the one? The philosopher described the role played by villainous economic factors, which were still up for discussion 2000 years later by authors like Michael A. Kaplan in an academic text called Friendship Fictions. I don’t think the concept of friendship can be quantified, but the monetary value of some of its indicators, or their equivalents, can be guesstimated.

Mercenary matters disrupt the bonds between tight male buds in Ira Sachs’s most recent two films. Love Is Strange (2014) is about the financial plight of two gay New Yorkers of a certain age after music instructor George (Alfred Molina) loses a teaching job in a Catholic school once the administrators learn of the wedding that formalized his decades-long relationship with Ben (John Lithgow), a painter. The two become victims of the progressive law allowing gay marriage. No longer able to muster the rent for their apartment, they are forced to live singly — and sadly — among assorted pals and kinfolk. Wherever they stay, and whatever their hosts’ intentions, they become intruders.

Their counterparts in Sachs’s latest, Little Men, by far his finest film and one of the best by anyone this year, are new neighbors and classmates in Brooklyn — not aged, rather coming of age. At 13 they do not have to deal head-on with larger social problems as do George and Ben, which are at most abstractions in their minds. Each supports the other’s goals and defends him from bullying or insensitive classmates as required. Hormonal development takes precedence over all else.

The boys are not lovers — although one cannot always be sure whether an attraction at that age is a platonic crush or the kernel of something more — but theirs is definitely an adolescent bromance in which, between games both outdoor and indoor, they navigate as a duo both the public and the private spaces they frequent. They blade (Jake, played by Theo Taplitz) and scooter (Michael Barbieri as Tony) like mismatched swans: Jake is klutzy, Tony the confident and graceful top man in their playful forays into neighboring parks and across busy streets. (Sachs turns sex-and-gender stereotypes upside down: Urban Dictionary refers to scootering as one of the gayest sports.) Aside from one fabulous field trip to a kids’ disco party in the city where the youths dance and flirt with neon necklaces hanging from their necks, and where Tony has a terrific scene demonstrating the resilience of kids his age, the exteriors were shot in the Brooklyn neighborhoods of Sunset Park, Williamsburg, and Bay Ridge. Experimental composer Dickon Hinchliffe of the British band The Tindersticks sweetly romanticizes these tender explorations with a bouncy, repetitive two-note melody that comes across as theirs.

Like George and Ben, they are immersed in the arts. Jake is a lank, pretty, introverted painter, whose dream is to gain admission to the LaGuardia School of the Arts. Tony is a charismatic, full-on extrovert, class clown and life of the party, who studies acting (he recites Strindberg at home) and, under Jake’s influence, wants to attend LaGuardia as well. He is as comfortable touching Jake affectionately as the latter is uncomfortable with such direct attention. Both gifted with fertile imaginations, they actually complete each other’s stream-of-consciousness stories.

Economics, of course, tends to trump everything else. Michael’s single mom, an immigrant seamstress named Leonor (Paulina García, better cast in the Chilean comedy Gloria), has for years rented at a low rate the storefront of a building belonging to Jake’s recently deceased grandfather, Max. Tenant and owner were close pals, reciprocating their heartfelt service as a palliative for loneliness. The dearly departed bequeathed the house to his children, who had grown up in it but left the area years before: Jake’s father, Brian (Greg Kinnear), and aunt, Audrey (Talia Balsam). Brian and wife Kathy (Jennifer Ehle) take Jake away from his school and friends in Manhattan to a new and very different environment in Brooklyn. Since Brian and Kathy get the house, Audrey — nothing but an intrusive reality who has to be dealt with — receives the store rent, and she wants a threefold increase, “still below market value,” she insists.

Fearless Michael is already out of place at school, but in a positive way; parvenu Jake is much more so, but his manner is offputting to the others. Combined with their daily proximity (Michael and Leonor reside a couple of blocks away from the house, but the storefront shop is the center of their lives), it is as if a divine matchmaker has arranged the friendship.

The boys are oblivious to the downside of gentrification. Assets and social stratification are not yet part of their vocabulary, but they will learn new terms when the inevitable showdown between interloper Leonor and the rightful heirs takes place. Class and country of origin become unarticulated ammo. (Earlier, tailored Kathy had bragged to plain Leonor, stuck as usual behind her noisy sewing machine, that she takes Mondays off “to get myself together for the week.” In a clever deployment of intertextuality, Leonor’s one close friend, Hernan, presumably a lawyer for the downtrodden who is played by Molina, probably earns less than Kathy’s flamboyant Latina maid.)

Sachs might be taking a cue from Fassbinder, who, more than most intellectual filmmakers, understood how deeply finances can undermine love not only within families, but also between friends and between families and friends. With George, Ben, Michael, and Jake, Sachs provides us with a multigenerational illustration of the cocoon that protects the young until it bursts and they begin to come of age, as well as the aftermath, when fate starts to overwhelm them with regularity, bump by painful bump.

The young can only be told so many times that he or she doesn’t understand an adult matter, before translating it into something comprehensible, and then, as in the case at hand, doing something about it. Sachs acknowledges the influence of Japanese master Yasujiro Ozu, whose I Was Born, But… (1934) and the later Good Morning (1954) deal with much younger children who go on strike against their parents (hunger in the earlier film, speech in the second). In a much less comic and cute manner, Jake and Tony decide to protest their parents’ apparent impasse by not talking to them. Children sometimes do this to each other beginning around the age of three in the process of relationship aggression, a form of punishment in which one kid withholds companionship from another. In Lysistrata, Aristophanes took a similar approach: The women of Athens and Sparta refuse to provide sexual companionship until their men desist from fighting each other.

The boys’ withdrawal provokes unexpected responses in their elders. Brian, an actor himself but a thoroughly unsuccessful, bitter one, loses his temper and tries to crush the boys’ artistic aspirations — especially those of his son’s perfect friend. Leonor, resigned to the turnabout in her relationship with her high-energy son, plays the fatalist, deflecting her agony onto Brian by repeating to him hurtful, intimate comments uttered by his father about what he considered his son’s failings as a man. Kathy, a psychoanalyst and sole breadwinner in the household — puppeteer to Brian’s marionette — borrows from her professional playbook to the point where acting and manipulation in the family home are indistinguishable. She is director of her husband’s finest, most believable performance, with their gullible son an easy mark as audience.

In point of fact, everyone in the film is a trouper, either on the stage or off. Is this Brechtian doubling, estrangement to make a point, or are all of them insincere, out of necessity or perhaps choice? With the exception of Hernan, the grown-ups are kind of mean. The boys — nice guys now, but who knows what they might grow into, given the noxious display of the genes they carry — could run out of combat options, which would signal the end of that delicious feeling of finding the one.

Sachs and frequent collaborator Mauricio Zacharias alternate writing drafts of the script — not dissimilar from the shared flow of imagination experienced by Tony and Jake. The filmmaker gets great performances from his cast, I’m sure owing in part to his particular method of working with them: no rehearsals, but one-on-one meetings. You might say the shoot itself is the rehearsal. Barbieri has been rightfully lauded at Sundance and in Berlin. A raw, bursting talent, the kid is already practicing Method, studying at the Lee Strasberg Institute in New York. In the film’s drama class opposite his real-world Strasberg teacher, veteran Mexican actor Mauricio Bustamante, he does a lengthy, improvised acting exercise, an instant classic in which he screams, verbatim and creatively reinflected, immediately after every word the man barks.

Óscar Durán, DP of choice of the great Spanish director Jaime Rosales (The Hours of the Day), gives the lower-middle- and working-class neighborhoods of Brooklyn an ethereal gloss, scenes appropriately textured and colored. (“He believes in the medium shot,” says Sachs.) In a film in which class differences and markers of individuality by adolescents are of paramount significance, production designer Alexandra Schaller and costume designer Eden Miller make props and materials sing.

In the movie, the one play in which Brian performs, for little or nothing, is The Seagull. Chekhov. What a brilliant decision, to include an intricate but rhythmic piece as a commentary on the characters negotiating Brooklyn, with their intertwined motives and agendas, and the theater piece’s fusion of naturalism and artifice. The juicy, well-integrated collision of social strata is as specific to the playwright’s Russia as Sachs and Zacharias’s rendering is to the borough in which the film is set amidst the lengthy labor pains that necessarily accompany contemporary gentrification. Viva la huelga!