A young mother and her four children move into a small apartment in Tokyo. Only the eldest, Akira, is known to the landlord; he and his mother Keiko smuggle the youngest boy and girl, Shigeru and Yuki, into the apartment inside suitcases. The elder sister, Kyōko, comes separately by train. Each of the children has a different father. Their mother does not allow them to go to school or be seen by others, and only Akira is allowed to go outside. After a few months, Keiko tells Akira that she has a new boyfriend, and that after she gets married, the children can lead normal lives, but Akira seems doubtful. Without warning, Keiko leaves home and is away for months, leaving only a small amount of money for the children. Akira is forced to take charge of paying the rent and other expenses and caring for his younger siblings. When they run out of money, Akira goes to see several men who may be Yuki's biological father and asks them for money. At length, Keiko returns, bringing all the children gifts, but soon leaves again. Though she promises she will be back in time for Christmas, she breaks this promise, and the season changes to the New Year and then to spring without her returning, forcing Akira and Kyōko into the roles of surrogate parents. Akira soon finds evidence that she has already married and left them forever, though he does not tell his siblings. Again running out of money, they are unable to pay their rent any longer and subsist on inexpensive food from the convenience store. On Yuki's birthday, she asks to go outside to wait for their mother at the train station. The siblings enjoy a day out together, and though their mother does not return, Akira promises Yuki that one day he will take her on the
Tokyo Monorail to see the airplanes take off at
Haneda Airport. Akira befriends two boys his own age at a game arcade who start frequenting the family's apartment, playing games and roughhousing, and he begins to neglect his siblings. The apartment is falling into disrepair with no one cleaning or keeping up with other chores. When Akira and the two boys go to the convenience store one day, they dare him to shoplift. Akira refuses, and the two boys leave him. Several months later, when the two have entered junior high school, Akira comes by their school and invites them over to play, but they refuse, and Akira overhears them saying that his house smells like garbage. In an apologetic gesture, Akira takes his siblings to a nearby park to play and buys them candy and toys at the convenience store. They start a garden on the veranda of the apartment, planting seeds from wildflowers inside instant noodle cups. Eventually the electricity, gas, and water in the apartment are all turned off. The children start using the public park's toilet to wash themselves and the tap there for their water. On one of these visits, Shigeru starts a conversation with Saki, a high school student who is cutting class, which blossoms into a friendship between her and the siblings, and she begins to visit them and help Akira and Kyoko care for the family. However, when she tries to help Akira out of financial difficulties by offering him money obtained through
enjo kōsai, Akira rejects it and runs away. With summer approaching, the children have little money and are growing weary. Akira goes out one day to watch a junior high school's baseball match. The team's coach spots him and, short a player, asks him to sub in. Akira joins the game and enjoys playing baseball. While he is away, Yuki falls from a stool while trying to reach for something and dies. Akira goes to find Saki again, finally accepting her offer of financial support, and they buy as many boxes as they can find of Yuki's favorite chocolate candies, which they place with Yuki's dead body in a suitcase. With Saki's help, Akira takes the suitcase to a field near Haneda Airport's runway. They sit and watch planes come in, and then he and Saki dig a grave and bury the suitcase. They then return to the apartment, and the film ends with Akira, Kyōko, Shigeru, and Saki still together, walking home. Saki now has her hair in pigtails, almost like the longer pigtails Yuki used to wear. ==Cast==