The premise of Boy is quite simple: a middle aged couple travels around Japan and fakes accidents because they know hapless automobile drivers would rather pay a little bit of money to make their troubles go away then confront them. Most of the time they get the oldest child, who is never given a name beyond Boy, to quickly jump into a car from the side. The drivers must be very guilty people because they all assume they have in fact hit the Boy in spite of the impossible logistics they are presented with.
The Boy is the main character of the film and he's as disturbed as you would expect a ten year old boy who works dangerous con jobs to be. Since his family moves around all the time he doesn't have any sort of perspective of place, he hears the names of cities they are in and ones they are going to but they are never more than names to him. The Boy also lacks the usual naivety and faith in others that are usually found in children that age; he sees the worst side of the strange adults he deals with and his parents are trashy criminals: in addition to being the mastermind of their scam, the Father is also abusive and manipulative. The Mother is actually not the Boy's real mother but he still prefers her to his father; she may treat him poorly and give in all too easily to his father but she at least occasionally feels bad and tries to make him feel better. The Boy is in the unusual position of being the most intelligent and mature person in most of the encounters he has with others.
Although the Boy is disenchanted with humanity he is not disenchanted with all lifeforms: he repeatedly tells his baby brother and the Mother about the aliens from outer space. These aliens actually care about one another and help each other out instead of greedily deceiving each other. Basically, the aliens represent to him what family represents to most children his age. Unsurprisingly, he sees himself as a part of this mysterious but ubiquitous race, presumably one that has been placed in Japan by mistake.
In addition to the fascinating characterization of the protagonist Boy is also interesting for its experimental style. Oshima experiments with still images and distortions (as in the scene in which the Boy wears someone else's glasses and everything is slanted) and especially with color: filters give scenes tone they wouldn't have otherwise, often suggesting the emotions of the Boy quite effectively.
Oshima shows Japan as a country striving to find a sense of itself much as the boy does, particularly in the scene where Japan's traditional colors of red and white are displayed prominently in the background: not on the familiar flag but on a giant Coca Cola billboard. It's also no coincidence that the family exploits automobile traffic and not something more traditionally Japanese.
With Boy Oshima managed to make a film that was simultaneously universal in its treatment of human nature, culturally relevant in its treatment of postwar Japan's national identity, and modernistically rich in its treatment of cinematic techniques.
