Ponyo is a 2008 Japanese animated fantasy film written and directed by Hayao Miyazaki. The film is loosely based on the Hans Christian Andersen story "The Little Mermaid" and tells the story of Ponyo, a goldfish who transforms into a human girl and befriends a five-year-old boy named Sosuke.

     The story begins underwater where Ponyo lives with her wizard father Fujimoto. Ponyo is dissatisfied with life under the sea and escapes, becoming trapped in a glass jar on the shore. Sosuke finds her and frees her, nicknaming her Ponyo. Ponyo uses her father's magic to transform into a human to be with Sosuke. This causes an imbalance in nature, resulting in a devastating storm.

     Ponyo's father comes to shore to force Ponyo to revert to her true form. Ponyo refuses, declaring her love for Sosuke. Her determination triggers her complete transformation into a human. The balance of nature is eventually restored, allowing Ponyo to stay with Sosuke permanently.

The film explores themes of love, responsibility, and the relationship between humanity and nature. The animation is done in Miyazaki's distinctive style, with hand-drawn watercolor seascapes and characters. The seaside village where Sosuke lives is based on Tomonoura in Hiroshima. The music was written by Miyazaki's regular collaborator Joe Hisaishi.

Ponyo was released in Japan in 2008 and went on to gross over $200 million worldwide. It received Animation of the Year at the 32nd Japan Academy Prize as well as several other awards and nominations. Critics praised the film's visuals and themes. Ponyo is considered one of Miyazaki's most accessible films for young audiences. With its imaginative story, vibrant animation, and endearing characters, Ponyo is a magical and heartwarming fantasy film.