So I got this idea from a photo I saw
One mermaid/man is an outcast. Lives by theirselves and so on. This is because the rest of the mermaid world thinks they are evil. They have a black tail, everything.
The other mermaid/man is a super happy, bubbly character and one day gets into trouble and the ‘bad’ mermaid saves them. The good mermaid, decides to repay them but eventually they fall in love so on.
Yeah, I just need a friend right now