The idea of this one popped into my head after watching the anime restaurant to another world which involves fantasy races coming into a Japaneses restaurant one day a week do to a magic spell. The idea I had would be the opposite with a guy coming into a brothel filled with fantasy girls. Not sure if I will right it or not but thought I would share none the less.
Sounds intriguing. Any thoughts on how "normal" the girls are by their own worlds standards? Also it might be interesting to have passages from the perspective of the pimp/madame. Those could be good for exposition.