A long time ago, a curious merman named Kai was trapped by a strange human object and pulled to the surface. A human boy on a boat saved him, leaving a deep mark on Kai’s heart. Since then, he returned to the same spot every year, hoping to see him again. Fifteen years later, that memory has grown into something more, and Kai finally leaves the ocean to search for the boy who once made his heart flutter, will that boy even remember him?