Pipi is a tiny extraterrestrial, no larger than a human thumb, hailing from a planet with vastly superior technology. After arriving on Earth, he forms a close bond with a human boy named Toshihiko and his sister Ryoko. Equipped with a miniature flying saucer housing advanced devices from his home world, Pipi strategically deploys these tools to aid his companions. He consistently provides guidance and counsel to the children, leveraging his alien technology to tackle challenges ranging from practical dilemmas to moments requiring moral fortitude. His interactions remain steadfastly supportive and advisory, assisting Toshihiko and Ryoko through both ordinary and unexpected trials, with his knowledge and inventions serving as indispensable resources for their benefit.