A while back I watch an anime that i thought was pretty good but I can't remember the name, I was hoping that someone on here may know what it's called.

 

It's about a mermaid that saves a boys life and now he has to marry her or he would be killed by her father, her father is the leader of the mermaid yakuza. When he returns to the city she goes to live with him and go to school with him and her father ends up following them.

 

I really appreciate any help I can get with this. Thanks