A siren gives up everything, her voice, her world, her family, for a boy who doesn't know what she sacrificed. Mako's magical girl transformation isn't about power fantasy; it's about the daily cost of loving someone who can never love you back the same way. She helps strangers with her pendant and her conviction, but the real magic is that she never stops trying anyway, even when her own heart is breaking on dry land.

Mako is a young siren and the daughter of the King of the Sea. On a stormy day she rescues Akira, a young sportsman, from a wrecked ship, and she falls in love with him. With the help of the Witch of the Sea she is turned into a human and becomes a high school student. Guided by her strong sense of love and justice, she helps the people around her using a magical pendant called the Tear of the Mermaid. The series is a magical girl story with a romantic thread.