Themm: Harukanaru Meikyuu

Long time ago, human beings believed in gods. But time has passed, and the humans stopped worshipping them. The gods got angry. The world plunged into chaos. Demons who looked like pretty girls have appeared, driving people insane. Five kings have sent brave heroes to find a magical stone that alone could restore peace to the world. One of these heroes is Lucido. Aided by a simple village girl, he bravely descends into a dungeon full of seductive monsters - but he should beware of the competition...

Themm plays very similarly to Raidy games: it is one big first-person dungeon crawl (solo) with randomly appearing enemies and turn-based combat. The enemies are, as the story implies, pretty and female; they disrobe upon defeat, which would already qualify this game for the adult genre, even if it weren't for the boss enemies who engage in full-fledged sexual activity with the hero.