I can't even remember which site I found it on but the MC was a female with horns, it was an RPGmaker game, initally set in a fantasy world and then you cross over into Earth. The race of the female was part demon-kind and she had to have sex on a regular basis to avoid some health issue (can't remember what), and this race was looked down upon by the ruling fantasy land race. The game starts off with the MC being a slave/servant in a palace. I can't quite recall the name of the race or the character but something like Coetexil - does that ring any bells? One thing I do remember reading is that the dev was a father-son combo and sadly the father passed away and the son has struggled to make updates ever since. Thanks in advance, and sorry for the vague clues.
