As summer vacation approaches, elementary school student Koichi Uehara finds a large rock on his way home from school. He brings it home, but when he washes it with water, a small kappa jumps out. The kappa calls "Ku" to him, so Koichi names it "Ku." Ku can speak human language and had been buried underground for hundr…Read full synopsisShow less
As summer vacation approaches, elementary school student Koichi Uehara finds a large rock on his way home from school. He brings it home, but when he washes it with water, a small kappa jumps out. The kappa calls "Ku" to him, so Koichi names it "Ku." Ku can speak human language and had been buried underground for hundreds of years. Koichi quickly becomes best friends with Ku; they bathe together, eat together, and sleep together. Other family members also accept Ku, making the little kappa a secret of the Uehara household. One day, Ku expresses a desire to return home to be with his companions. To help Ku understand the outside world, Koichi secretly takes him out. Ku is shocked to discover that the environment has changed beyond recognition, finding no place suitable for kappa survival and no companions. Seeing Ku's sadness, Koichi feels distressed as well. They travel together to Tono Prefecture, where legends about kappa are still preserved. In the beautiful nature, they find a place suitable for kappa life, and Ku happily swims in the clear river while Koichi rejoices for him. However, they cannot find any other kappa there either. When Koichi overhears villagers saying, "Catch one kappa and get ten million yen!", he hurriedly takes Ku away from there. Upon returning home, Koichi is surprised to encounter a tabloid reporter who heard that the Uehara family was keeping a kappa and insisted on taking photos. Ku's secret is finally revealed to everyone. Koichi's father is ordered by his company to have the kappa appear on television. For the sake of the Uehara family, Ku agrees to participate in the TV program. However, among the guests, Ku sees someone who closely resembles his father's killer. As fear surrounds Ku, an accident occurs at the live TV show. Ku desperately escapes outside, but wherever he goes, he sees crowds of people. To escape the humans that frighten him, Ku climbs Tokyo Tower. The scorching summer sun leaves him exhausted. Overlooking the city, Ku whispers alone: "I can't find a quiet place anywhere. This is the nest of humans. I can't take it anymore. I want to go to my father..."
