How dark do you want this to go ?
I'm trying to wrap my head around this game, as I do have a few ideas right now spinning that could include the Neko-men.
I am actually leaning towards a fantasy setting, where the Neko-men are made and trained by an evil wizard to serve him in all ways. That way the story is open, or will eventually be opened to others.
The Neko-men could actually be, after having been sufficiently trained, been "enhanced" further to become a warrior breed for him, or those that do not fit, will become a slaves and rewards to those that do.