This sweet, innocuous, boy-meets-boy story is set in a housing complex in South London, a place where no secret is safe. Neighbors overhear conversations, complain about the music blaring from behind apartment doors, and glimpse any and all comings and goings along the motel-style walkway connecting the lives of these blue-collar folks. The refreshing setting is one of the nice touches in Beautiful Thing, which at its best evokes the working-class, bittersweet comedy of Mike Leigh in movies like Life Is Sweet. More often, though, it lapses into the tidy conventions of a progressive after-school special.

Adapted by Jonathan Harvey from his play, Beautiful Thing takes its time in acquainting us with the denizens of the housing project, and some of the broadly drawn supporting characters, like the Mama Cass-worshipping teenage busybody Leah (Tameka Empson), probably worked better on stage. When Harvey and director Hettie MacDonald, making her feature debut, get around to the budding relationship between high-schoolers Jamie (Glen Berry) and his next-door neighbor and classmate Ste (Scott Neal), the film finds a groove. There are some wonderful moments: the boys tentatively getting physical in Jamie's room while on the other side of the wall Jamie's divorced mom, Sandra (the terrific Linda Henry), and her boyfriend (Ben Daniels) watch The Sound of Music.

Henry steals the movie, partly since hers is the best-written character, partly because the film's sentimentality is tempered by Sandra's vulgarity. Beautiful Thing isn't sure whether it wants to embrace fantasy or depict real life; in the end, it settles for a bit of both. Screens Monday at the Kendall Square at 7 and 9 p.m., and on Tuesday at 2 and 4 p.m. Director Hettie MacDonald and writer Jonathan Harvey will appear at tonight's 7 p.m. showing.