Loverbird's Manga

The story was extremely intriguing towards the recent chapters, because at first I was completely deceived by the cover of the story that I assumed it would be about human x mermaid romance. But instead, it shows complex issues of how to deal with trauma, coping with lost beloveds, and even dealing with phobias. The whole entire story handles a lot of dark themes, and impacting the main character and everyone around him.

Also to keep in mind, this story is definitely leaning towards yandere, and a toxic relationship between the protagonist and deuteragonist.