As a mermaid, she has a life span of five hundred years, which may be too long for humans. The mermaid only thinks it is a short moment. But since she fell in love with a human being, everything has changed. Since they met and fell in love, the process was not romantic, but it was too painful. When he reached it, the mermaid decided to use the remaining five hundred years to wait and use everything she had to wait for her lover's next life. However, she was afraid that five hundred years would be too short, afraid that it would be too late, and afraid that she would not be able to wait. What would be the meaning of this long life without him...