The main cast includes four young animal heroes: Seitaro Usagi (a rabbit), Risu (a squirrel), Kuma (a bear), and Penguin (a penguin), whose initials combine to form U-Ri-Ku-Pen. These youthful animals constitute a brave rescue team dedicated to saving those in danger. Additional members of the team are a dog, a boar, a deer, a koala, a mouse, a seagull, and a lion. Upon completing a mission, the animals receive a reward, and viewers also have the opportunity to win prizes. Audience engagement is promoted by having them submit guesses each Friday about which creature will ultimately save the world, with each mission spanning a full week of airtime. Created by Mitsuru Kaneko, the series was broadcast on certain American local TV stations that serve the Japanese community.