A Japanese coastal city cannot be in a calm state. If a man goes sailing, his family has to wait for him at home. The boy Souska turned five years old not so long ago. His father was an employee of a fishing trawler. Therefore, he was not in the house very often. Rhys's wife was very upset by this situation. She is a nurse and always brings up her son by herself.

The descent was helped once by a small fish, which he later called Ponyo. The kid really liked this inhabitant of the sea. Therefore, he did not want to part with her for a minute. The main character put it in a bucket and carried it everywhere with him. The fish also wanted to communicate with her savior. But, on the ocean floor, she left her parents. Ponti's father is an excellent experienced wizard, and his mother is a sea goddess. In reality, the fish had the name Brunhilda. Then she was returned to the sea waters and imprisoned inside a magic bubble. However, the brothers and sisters managed to help her, and the fish ran away. Ponyo asked the ocean to help her. She met Sousuke again, turning into a real girl.