Yuna ist eine Karatemeisterin, die mit ihrer Großmutter zusammen in Japan lebt. Plötzlich wird sie von der Nachricht überrascht, dass ein blaues Monster in der Stadt für Unruhe sorgt und sie macht sich gleich auf den Weg, um den Störenfried zu finden.
In the pilot episode, after the events of Leroy & Stitch, Lilo is now an adult and she has a boyfriend and a daughter, making Stitch to leave Hawaii and blast off into space after stealing a Jet Scooter, while acting totally nuts and goes back to his old programming ways of destroying things. An attempt to recapture Stitch is made, but he makes an emergency landing on Earth. Stitch finds himself on an Okinawan island to search for food and go back to Hawaii and tells Lilo he's sorry for running away from home but instead he meets a young girl named Yuna. After bonding during a storm, the two become friends.