Ah, I stumbled upon this and was instantly curious, because I am quite obsessed with the story of the little mermaid...and aaahhhhh....
this is really just a soft and touching story...and how lovely...that the MC had such a great love for the beloved mermaid, that he would never lose hope of finding them, that he would still find them, for their sake, should they return one day...
and wow, that persistence, that beautiful persistence is just so touching. Gosh you can't imagine how I'm crying right now. It's really quite beautiful.
edit:
And aaahhh!! forgot to say, but the writing is also so touching, I could definitely feel the longing for the mermaid with the words. And it was also just so bittersweet to realize what the dates meant --- and yet also so comforting to see that no matter how much time has passed, there are still some who continue to remember those swept away, refusing to forget the cherished memory of them.