Tangerine is a heartwarming tale of humanity punctuated by the clack of prostitutes' heels on sun-baked L.A. streets, by screaming matches in divey motels, and the admonishments of a doughnut-shop owner threatening to call the cops if everybody doesn't shut up.

With a spirit of genuine curiosity and generous fun, director Sean Baker dives into a certain subculture - transgender sex workers, the men who troll for them, the dealers and pimps trying to control everything - cruising around the seamier stretches of Hollywood on the day (and night) before Christmas. Baker's movie was shot with iPhone 5s, giving it a jumpy, in-your-face, verité vibe. The December light is quite lovely, too.

Tangerine stars newcomers Kitana Kiki Rodriguez and Mya Taylor, African American transgender women with more than a passing knowledge of the activities in their neck of the woods, a neck of woods lined with taquerias, coin laundries, gas stations, loan shops, empty storefronts. Good friends in real life, the pair met with the filmmaker - whose 2012 character study, Starlet, with Dree Hemingway, explored another subculture, the L.A. porn industry, and the gang was off and running.

Rodriguez, as Sin-Dee, just released from a month in jail, is literally running - running around trying to find Chester (James Ransone), her pimp, her beau. Alexandra (Taylor) has just informed her that Chester has been unfaithful, seeing another girl - a white girl - while Sin-Dee was gone. Revenge, or at the very least an explanation, is in order.

A parallel plot line follows Ramzik (Karren Karagulian), an Armenian cabbie who picks up passengers, discharges passengers, and makes frequent sorties along the blocks known for transvestite hookers. Turns out that Ramzik, who is married, with a little girl and a watchful mother-in-law, is well-acquainted with Sin-Dee and Alexandra, too.

Baker gets great, sly, unforced performances from his two leads, but it's not all a rollicking good time: There are moments of quietude, inquietude, moments when a sense of wariness and loneliness settles over the women. Sometimes, Sin-Dee and Alexandra's friendship - and nothing else - keeps them from falling apart.