What do you name a 12-year-old Afghan girl whose mother disguises her as a boy to spare her the miseries reserved for females by the repressive Taliban regime? Father and brother have been killed; women are forbidden in public without a male family member; at least a ''son'' can travel freely to earn a wage. A scrappy local kid figures out the ruse but keeps the secret and gives her a resonant alias. And thus the sad and stunning drama Osama has nothing to do with the al-Qaeda terrorist bin Laden, but everything to do with the hopelessness and oppression that marked the Taliban's fundamentalist rule in Afghanistan. The movie is a rare uncensored postcard from a ruined place, a document at once depressing and hideously beautiful that sketches the real hardships of trampled people -- specifically women -- with authority and compelling simplicity.
The first entirely Afghan production since the Taliban's fall, ''Osama'' is also a feat of understated authenticity. Siddiq Barmak, in his feature directorial debut, shot in Kabul with a largely nonprofessional cast, including Marina Golbahari, who plays the terrified title character with piercing believability. Every detail of her bewildering new life threatens to give the girl-as-boy away, from her unfamiliarity with the way men pray, to her high voice; and it's easy to assume that Golbahari, born in 1991, wasn't acting fear, but feeling it. Rounded up with the boys by the Taliban's religious police and sent to a compulsory religious school, the disguised girl is thrown even deeper into danger. There is, be warned, no happy ending.
There are, though, details of such well-chosen specificity that Barmak compresses whole sub-dramas into single shots: An old mullah modestly demonstrates the proper ritual washing of the genitals to a crowd of skinny naked boys; a foreign photographer is arrested for being a foreign photographer. And every time a woman matter-of-factly dons the head-to-toe burka that erases her female personhood, we're shocked anew by what ''Osama'' tells with the intimacy of an everyday diary entry.