When Sosuke, a young boy who lives on a clifftop overlooking the sea, rescues a stranded goldfish named Ponyo, he discovers more than he bargained for. Ponyo is a curious, energetic young creature who yearns to be human, but even as she causes chaos around the house, her father, a powerful sorcerer, schemes to return Ponyo to the sea.

In Italy in the 1930s, sky pirates in biplanes terrorize wealthy cruise ships as they sail the Adriatic Sea. The only pilot brave enough to stop the scourge is the mysterious Porco Rosso, a former World War I flying ace who was somehow turned into a pig during the war. As he prepares to battle the pirate crew's American ace, Porco Rosso enlists the help of spunky girl mechanic Fio Piccolo and his longtime friend Madame Gina.