Maco, the Mermaid

Mako is a young siren and daughter to the King of the Sea. In a stormy day she rescues the young sporto Akira from a wrecked ship, but ends up fallign in love with him. So, with help from the Witch of the Sea, she's transformed into a human, and becomes a highschool student who helps everyone with her strong sense of love and justice and her magical pendant, the "Tear of the Mermaid"...

Super sadly this is the only one of its kind