Children are naturally attached to their parents, requiring them as guides in a world they don't yet have the capacity to navigate alone. Mikio Naruse's 1960 film Autumn Has Already Started (秋立ちぬ)
shows a relatively normal little boy dealing first with the death of his father and then abandonment by his mother after moving to Tokyo from the country. Without indulging in sentimentality or melodrama, Naruse depicts the natural process of growing up being sabotaged by fairly common catastrophes. It's a beautiful and sad film.
Hideo (Kenzaburo Osawa), a prepubescent boy, travels with his mother, Shigeko (Nobuko Otowa) to Tokyo where they've come to live with some relatives. It's a few years after prostitution was made illegal in Japan and Shigeko finds work in one of the hotels that filled the new vacuum--as one of the hostesses, it's Shigeko's job to act as a surrogate wife for a client; feeding him, dealing with his laundry, sleeping with him, and going out with him. A businessman played by Daisuke Kato takes a liking to her and soon wants to marry her.
Meanwhile, Hideo strikes up a friendship with a little girl named Junko (Futaba Ichiki), the daughter of the hotel's madam. Junko believes her father has two wives--her mother and another woman whom he spends more time with. Later in the film Junko meets her two spoiled half-siblings who are very rude to her.
Hideo says she's lucky to have a father at all, though he denies having cried at the death of his own father when Junko repeatedly asks him. The film is good at showing how children are bad at picking up on each other's emotional cues as Junko takes everything Hideo says at face value, not guessing his pride won't let him admit he cried. The two children are obviously forming something like a romantic bond, though Junko asks her mother to let Hideo be her brother. But, while a teenage Hideo might blow off a meeting his mother to hang out with his girlfriend, we see Hideo in the film unselfconsciously bidding Junko good day at a mall when he hears that his mother is also there.
Which is a subtle way of showing how hard it is on him when his mother disappears without warning--we learn later that she's gone to live with the businessman in another city. Hideo starts spending more time with Junko and the two seem to flirt with the idea of running away, having her mother's driver take them to the bay where we see the two meandering and playing. But soon Junko wants to go home, an option that Hideo really doesn't have.
There's a subtle theme of the city being inherently disruptive of family compared to the country. In one memorable scene, Hideo looks over some rooftops with his last companion from home, a big helmet beetle looking very much out of place.