Marina is a young mermaid who is fascinated by the human world and one night saves a prince when his ship sinks in a terrible storm. She falls in love with him and goes to the sea witch who gives her a potion to turn Marina into a human but in turn takes away her voice. She is told if she fails to marry the prince, she will die and dissolve into sea foam. Unfortunately, she does fail but is given a second chance at life if she kills the prince and becomes a mermaid again. But she is unable to carry it out and accepts her fate. Based on the fairy tale by Hans Christian Andersen. from Toei. Produced at its in-house animation studio.