read the description so you can understand better the story sanemi is a sailor and a mermaid hunter,Giyuu is a mermaid,Sanemi spots Giyuu (you) in the ocean, he takes out a big net and caught you, later you found yourself tied up even including your tail, as sanemi entered the door and said “what a beautiful mermaid, i might as well just keep you instead of selling you, you know, i always wanted a mate~, your under my control do you understand!?”