"Nobody Knows" is filmed with the simplicity of the greatest art, and nothing overtly violent happens during its nearly 2 1/2 hours. Yet the Japanese director Hirokazu Kore-eda has made a film that's almost physically painful to watch. Spare and elegant and harrowing, it's an ode to childhood trust being stretched until it snaps.
A mother (You) and her 12-year-old son, Akira (Yagira Yuya), move into a second-story flat in an anonymous Tokyo apartment. They carry a set of heavy suitcases up the stairs and unzip them, and out pop three more kids: 10-year-old Kyoko (Ayu Kitaura), 7-year-old Shigeru (Hiei Kimura), and 5-year-old Yuki (Momoko Shimizu). The landlord doesn't rent to families with more than one child. The mother, Keiko, instructs the younger three not to leave the apartment; none of them goes to school, although the older two would like to.
We learn that Keiko isn't so much a free spirit as an immature flake. She had dreams of being a pop star once, before having her children by different fathers, and she acts more childishly than her oldest son, who runs the household and keeps the others in line with the intensity of a factory foreman. Keiko has a new boyfriend somewhere who hasn't yet been told about the brood; she takes off with him for a week or so, leaving Akira in charge. She comes back once, then not at all.
"Nobody Knows" is based on an actual case in Japan in the late 1980s that, by all accounts, turned out worse than what we see here. What we see here is bad enough: days slowly building up and childhood slowly being ground down. Akira, as the family's representative to the outside, buys the groceries and, when he has to, cadges money from one of the younger kids' shiftless fathers. He's also a typical 12-year-old who occasionally brings schoolboys home to play videogames -- they hang out until the apartment's smell gets too much for them -- and who develops a crush on a square-peg rich girl named Saki (Hanae Kan) who becomes the four children's closest outside contact as the months stretch on. She understands the authorities can't be notified or the children will be split up. And besides, Keiko said she'd be back, didn't she?
Kore-eda ("Maborosi," "After Life") makes movies that are hushed and watchful, slow without ever being boring. In "Nobody Knows," he keeps the camera at kid-level, so we're right there with mischievous Shigeru as a ball of clay rolls onto the balcony and beyond the limits of his universe. We see Kyoko plink away on a toy piano as her mother's promise of a real one fades into memory. Little Yuki is adorable, beloved by her siblings, yet her wide eyes grow duller and duller as she crayons on and on.
If there's a problem with the film, it's that these children never fight, never have tantrums, never go stir crazy. Anybody who has kept a 5-year-old inside on a rainy day knows that's a physical impossibility. At the same time, there's something ineffably touching about watching the four wait, obediently, for mom to come home, as though she had merely stepped out to the store. At a certain point each child's hope becomes a false front for the others, and that, somehow, is sadder still.
"Nobody Knows" is graced with a gentle music-box score by the Japanese acoustic guitar duo Gontiti and with a performance by the adolescent Yuya that, for all its quietness, is reminiscent of Jean-Pierre Leaud's in "The 400 Blows." This movie delivers only one blow, but it's the kind that forever alters the adults these children will grow up to be. Kore-eda shows us cruelty and unexpected kindness, desperation and resilience. After a while they merge into what Akira and his siblings recognize to be their future.
Ty Burr can be reached at email@example.com.