A young girl, Chihiro, becomes trapped in a strange new world of spirits. When her parents undergo a mysterious transformation, she must call upon the courage she never knew she had to free her family.

The story is set in 1963 in Yokohama. Kokuriko Manor sits on a hill overlooking the harbour. A 16 year-old girl, Umi, lives in that house. Every morning she raises a signal flag facing the sea. The flag means “I pray for safe voyages”. A 17 year-old boy, Shun, always sees this flag from the sea as he rides a tugboat to school. Gradually the pair are drawn to each other but they are faced with a sudden trial. Even so, they keep going without running from facing the hardships of reality.

The son of a sailor, 5-year old Sosuke lives a quiet life on an oceanside cliff with his mother Lisa. One fateful day, he finds a beautiful goldfish trapped in a bottle on the beach and upon rescuing her, names her Ponyo. But she is no ordinary goldfish. The daughter of a masterful wizard and a sea goddess, Ponyo uses her father’s magic to transform herself into a young girl and quickly falls in love with Sosuke, but the use of such powerful sorcery causes a dangerous imbalance in the world. As the moon steadily draws nearer to the earth and Ponyo’s father sends the ocean’s mighty waves to find his daughter, the two children embark on an adventure of a lifetime to save the world and fulfill Ponyo’s dreams of becoming human.