Kiyoshi Kurosawa, the director of Tokyo Sonata (2008), has no relation to that other great Japanese director by the name of Kurosawa, but if the skill he demonstrates in constructing this particular story is any indication, he is indeed great. Known for his horror films, this Kurosawa undertook something a littledifferent with Tokyo Sonata.
The film examines a middle class Japanese family and the tensions they each experience as their desires clash with external forces, such as the slumping economy and societal pressures. It primarily seems to be a critique of authority, how it's being undermined in Japan.
In the beginning of the film, the father of the family, Ryuhei, loses his job because of outsourcing – Chinese workers are apparently much cheaper. But he doesn't tell his family the news. Instead, he pretends to go to work every day in his suit – but then waits in line, looking for a new job while collecting unemployment checks. Eventually he takes a job as a janitor, cleaning bathrooms in a mall. Before going home, he changes back into a suit to keep up the appearance that he still has his old office job.
Meanwhile Kenji, his younger son, desperately wants to learn to play the piano. But Ryuhei sternly refuses to pay for lessons. So Kenji saves his lunch money and pays for them in secret, learning from his teacher that he has a talent for it. And Takashi, Kenji's older brother, joins the US military to fight in Iraq, also without Ryuhei's approval. And when Ryuhei finally discovers Kenji, he attacks him in a rage, causing him to fall down the stairs. Kenji suffers a minor concussion. It is Ryuhei's very powerlessness that causes him to so desperately want to assert his authority, but this is ineffective and only leads to his family's suffering. This is also implied to be true of Japan as a whole: the economy is currently slumping and there is no military. Japan is unable to protect itself from either economic threats, such as globalization, or military ones. So the country is similarly powerless, and similarly places arbitrary and overly restrictive boundaries on the behavior of its citizens.
After about this point in the story, the film begins to lose its realist edge. All the events seem driven by preceding events; events as they apply to all of Japan or segments of Japanese society logically lead to their consequences on the individuals in the family. But at this point in the story, not only do several things happen to each member of the family which were not only not at all set up from previous events in the story, but are implausible or surreal enough to merit skepticism.
For instance, Megumi, Ryuhei's wife, is kidnapped by a burglar but becomes willing after seeing Ryuhei in his janitor's uniform at the mall; she drives him to the beach, where they spend the night in a small house. That night she wakes up and sees a strange light over the ocean; the next morning, the burglar is gone. After Megumi sees Ryuhei at the mall, he wanders into the city and is knocked over by a car, unconscious and seemingly dead. Kenji, meanwhile, unsuccessfully helps a friend run away home. He is caught trying to sneak onto a bus to get out of town, and spends a night in jail after being uncooperative with the police.
The next night, all three members of the family return home and have a quiet meal together. Then, several months later, Kenji plays Claire de Lune at a piano audition and completely blows away the other competitors in a display of not only his technical skill, but his emotional competitiveness, his parents watching proudly in the background.
I think this final section of the film is highly ambiguous. Like a dream, it is left open to interpretation. It's possible all of it is a dream, or a fantasy – an overly rosy way for things to turn out that isn't entirely realistic. The point, I think, is to finally show how to escape the cycle of feelings of powerlessness and impotent displays of authority. And that is simply through tolerance of yourself, but of others. This is why Ryuhei wears plain clothes for the first time in the film in this final scene, and why we see that he now supports Kenji's piano playing.