Yuuna is a young 7-year old 2nd grader, elementary-school student who lives on a fictional island off the shore of Okinawa called Izayoi. Living on Izayoi, she learned and studies karate, living a rather normal life, but having to deal with minor problems living with her grandmother, Obaa. However, one day she meets a strange creature that has come from the depths of space, Stitch.