A picturesque mountain village situated in a remote woodland area has become the summer camp destination of choice for a group of five elementary school children. Left to their own devices and without adult supervision, the youngsters spend their days taking pleasure in the flora and fauna of the surrounding wilderness. Their idyllic escapades soon take a startling turn when they stumble upon an injured creature that appears to be a small dog. They take the wounded animal, whom they call Pochi, under their wings but soon discover that he is actually an alien with an important mission. Pochi discloses that there is a valuable substance on Earth that is highly desired by extraterrestrial beings throughout the universe. The alien had almost found it but got hurt during a fight and had to abandon his search. The children save Pochi's life and, in exchange, he offers to take them on an adventure. When Pochi asks the youngsters where they would like to go, they reply that they want to explore as much as possible. Without hesitation, Pochi whisks them away to the moon, where they embark on a breathtaking journey. As they travel, they realize that the coveted substance is an essential ingredient in Japanese cuisine. To their surprise, one of the children happens to have a sample of the mysterious substance in their pocket.