Saw this picture in the Inspirational Thread and just had to use it! Anyway...my idea is kind of like the Little Mermaid type female. But instead of her trying to get above the ocean and be with a human male, she has fallen in love with the sea sorceress's son. She is a daughter of Neptune and the merpeople have been at war with the Octopus and their Sorceress Queen for decades.
Going against her father's wishes, the Princess wanders into Octopus territory while looking for a coral that could help heal some of their injured people. She's captured by the Sorceress's son and decides to let her go instead of taking her prisoner. He understands that she would be a good dealing chip in the war, but he knows she isn't a fighter and that the others of his people might hurt or kill her. He doesn't like the thought of senseless killing or using bribery.
It doesn't take long for her to start sneaking back to that area in hopes of seeing him again and thanking him, since she just swam off as soon as he let her go.
***Basically, a forbidden romance game involving a mermaid and an octopusman. We can discuss in PM just how far the romance would go and what not.
So yeah, PM me with interest or if you have an idea other than the one I posted.