 Se-hwa plans to turn her fishtail into a pair of human legs and live up on land with Dam-ryeong, but is unable to do so due to having not reached adulthood yet.Devastated by the news of Dam-ryeong's marraige, she decides to leave him forever.Nevertheless, Dam-ryeong's love for Se-hwa forces him to leave his wife after the marriage and jump into the ocean to look for her.