Mermaid Melody Pichi Pichi Pitch Pure

After a powerful foe met his end, Kaito and Lucia were finally reunited; but they don't live happily ever after. Though he promises to return to Lucia someday, Kaito decides to go to Hawaii, become a better surfer, and try to find himself again; but along the way, an accident causes him to lose his memory and he ultimately falls in love with another woman. In the mermaid world, things fare just as poorly: with Sara gone, a new mermaid named Seira has taken her place and constantly shows up in Lucia's dreams, warning her about troubles that lie ahead. As if things couldn’t possibly get worse, a new powerful villain named Mikeru has appeared; not even the strongest mermaid song can harm him! Can Lucia get back the one she loves and defeat her enemies?