Ariel is a dreamy young mermaid, daughter of King Triton, who is tired of her life as a princess under the sea. Her greatest desire is to leave the seabed and have a normal and peaceful life on the surface. The witch Úrsula discovers her desire and, therefore, in exchange for her precious voice, she offers her a totally human body. Ariel accepts, moved by her passion to know the terrestrial world and because she is in love with a handsome human prince. But things will not be easy for Ariel, since the witch Ursula hides dark intentions.