Satoshi Sugita is eleven years old. His mother died when he was born and now his father, a rather unsuccessful painter, has died in a car accident. Satoshi returns to the small town by the sea where his father grew up and his grandparents still live. He is deeply shocked by his father’s death. Satoshi believes that it is his fault and so stops talking. Everyone in the small town has heard the story of the boy’s misfortunes. The children in the neighbourhood can’t wait to meet Satoshi. However, it isn’t long before the boys exasperate Satoshi by throwing his cell phone into the sea: on it was his father’s last message before dying in the accident. Satoshi is devastated. But then the friendliness of the townsfolk makes itself felt and he gradually finds a way out of his grief and loneliness. Particularly helpful are Okina, an elderly doctor, and his granddaughter Ayumi, whose parents aren’t alive any more either. Though above all it’s the sea that enthrals him, arousing an enthusiasm like his father had once felt. Satoshi decides to participate in Hiwatashi, a ritual only performed at this spot. It starts off with the children having to swim three kilometres in the open sea. All those who accomplish the feat become members of the chosen circle permitted to watch over the holy fire of Chitosebi. For Satoshi, this challenge turns into his return to life.