Fujimoto, a once-human Magician (fantasy)/scientist, lives underwater along with his daughter, Brynhildr, and her numerous smaller sisters. While she and her siblings are on an outing with their father in his four-flippered submarine, Brunhilde sneaks off and floats away on the back of a jellyfish. After an encounter with a fishing trawler, she drifts to the shore of a small fishing town in a glass jar where she is rescued by a five-year-old boy named Sōsuke. Shattering the jar open with a rock, Sōsuke cuts his finger in the process. Brunhilde licks his wound causing it to heal almost instantly. Sōsuke names her Ponyo and promises to protect her. Meanwhile, a distraught Fujimoto searches frantically for his lost daughter whom he believes to have been kidnapped. He calls his wave spirits to recover her, leaving Sōsuke heartbroken.