Technically shounen ai??

It a manga that came out a bit ago about a crew of pirates “stole” this mermaid. Like he technically wasnt a mermaid but he had really rare features (i think like white hair and smth else) and was treated like treasure by the people who had him before.

I cant remember too much since its been so long but I do remember the crew treating the mermaid like family and the captain lowkey always being represented as an old/grumpy bear.

Please help Its been stuck in my mind and I cant remember ┗( T﹏T )┛