When ten-year old Riku arrives in a town to attend his new school, there isn't a soul in sight. The town is contaminated, after all, by radioactivity unleashed by the disaster that occurred in Fukushima in March 2011—a level-7 nuclear power plant accident. Riku has moved to the town, together with his father, a doctor, but there's nothing for a child like him to do there everyday, except to go to school and come back home again, since radiation levels remain high. Forbidden to go outside and play, Riku gradually loses his zest for living. The father, worrying over how broody he becomes, sends him off to a school nestled in the natural surroundings of a wintry mountain. Soon, through his exchanges with the denizens of the mountain, Riku begins to learn about the majestic force of nature. Returning to his town, though, Riku can't help but realize that all the adults are cowering in fear at the threat of radioactive contamination. He then begins to ask, what is life? What is a human being? How should a human being, existing at the top of the food chain, live on this earth? These are some of the themes explored in this poignant tale of the spiritual growth of a boy living in a post-nuclear accident Japan.

Riku and the Kingdom of White is based on interviews with children who continued to live in Fukushima in the immediate aftermath of the nuclear accident. Many of them, in fact, continued to reside within a fifty-kilometer range from the radioactive site. The food supply had been cut off and the power supply was erratic at the time, but the children, nonetheless, as if to dispel the anxieties of the adults, remained lively and cheerful. Many of them also attended the outdoors school set up by the NPO, "Fukushima Kids." This project, which was made possible by donations from both inside and outside Japan, is now in its fifth and final year. Over time, it has shown that bringing children into contact with nature can help spur their emotional and psychological development. Riku and the Kingdom of White, based on the true stories of children who participated in the "Fukushima Kids" project, is a testament to this truth, and a tribute to the children who experienced the nuclear accident firsthand. Depicting how they tided over the trauma, day by day, both emotionally and physically, Riku and the Kingdom of White paints a touching picture of children who, instead of being mired in despair, remain undaunted and filled with hope. Children are the future, after all. They are the hope of the earth.