the story about two princes has an older sister who adores her very much, but the massive evil power corrupts their kingdom and sinks to the bottom of the ocean the princess does her role to save her merpeople and her brother's to safety. she makes her brothers separate their life in the land and sea (Kaito) (Gaito). she does anything to save her brothers to have a normal life. she makes Kaito forgotten the life of the sea and have the life of the surface and Gaito being a stubborn prince to protect her sister. when the princess of the ocean saves the kingdom with her power in exchange into deep slumber she gives her pearl to Gaito to keep it safe, the only thing to wake her up is her song from the voice of the seven princesses from the seven kingdoms of the seven seas. (I don't own the anime!!!)