Right, I remember that at the beginning of the game, but then suddenly the main character stopped mentioning it for a while, and I started to forget about it. Then, during the sex scenes, the reason didn't seem to be about freeing the demon; it felt more like it was just for fun, in my opinion. He should have had internal thoughts about his goal, with more focus on the actual reason he was there. As it stands, freeing the demons feels like a side quest in the way it's being handled.
Not gonna lie, this is the only porn game where the world is more interesting than the sex itself, lol. I wish there were another novel like 'Twisted World' that expands more on the world and the characters, etc., instead of forcibly ignoring the world and focusing solely on sex.