So, I had this really dumb idea. It's a breeding season style game, but it's in kind of a more modern setting.
MC is a breeder that is being sent to a lab to inseminate monstergirls. However, when he gets there, he realises that things are not working like they should. Indeed, instead of there being monstergirls in pen to inseminate, the scientists are in the pen, gagged and tied up, and monstergirls in scientists coats are manning the machines.
Then, he gets informed that this lab is a test site by the monstergirl union. There are a lot of abuse by human staff on the monstergirl workers, so they decided to see if the scientists would be better test subjects. They also believe that by studying and comparing human reproduction with monstergirl breeding, they can reach breakthrough results.
So, in the end, our breeder gets to inseminate scientists while performing experiments. On the side, he also has to deal with horny monstergirls who, despite their utmost efforts can't quite resist having a human male available without getting ravenous.
You need to make discoveries to unlock funding so that you can 'recruit' more workers. Obviously, monstergirls are being sold as slaves, and scientists are hired like regular workers, but when they come in, you get to break in the scientists and to suit up the monstergirls so that they can help with the research.
It would play a bit like breeding season used to play, although it would be focused on individual characters, and I am not sure I would add randomization. There would be a bit of a corruption/bdsm theme for the human girls, while you would get to date the monstergirls that you are researching things with.
That's about it.