Kanao the youngest daughter of the king of the sea is not satisfied with a simple life under the sea, she is very curious about the human world and lives with the dream of being able to be part of that world, after the shipwreck of a ship, she saves a young man named Tanjiro, falling in love with him, to be able to live on the surface she disobeys her father and makes a deal with a sea witch, who gives her legs for a very high price, she agrees to be with the one she loves, but the witch will not let her have a happy ending.
Kanao as Ariel
Tanjiro as Prince Eric
Zenitsu as Flounder
Inosuke as Scuttle
Tengen Uzui as Sebastian
Gyokko (female versión) as Ursula
Daki as Vanessa
Karaku and Urogi as Flotsam and Jetsam
Kanae, Shinobu, Aoi, the butterfly triplets (being older) as Ariel's sister
Sanemi as Grimsby he would later meet Kanae
Mitsuri as Carlotta
Obanai as Louie
Gyomei as Triton
Muzan as the priest
Kyojuro as Max