Lukia Nanami turns seventeen just after her family moves to a town by the sea, and on her first walk down to the beach she pulls a drowning surfer out of the water. The next day he turns up as a classmate at her new school, with no memory of her and insisting a mermaid saved him. Her mother Lucia then tells her whose daughter she is, and Pink Hanamori picks the mermaid princesses' story back up a generation on from the original manga.