AVANTGARDE - He Who Vowed to Create a Demon Harem Ver1.12 Final (Official Translation) - Adult Sex Game

The year is 1887.
Humankind has been assailed by demonic invaders from hell. For a time, humanity's future was uncertain... until brave soldiers arose who fought back the demons. These soldiers are called heroes.

One such hero, a man named Theo, has a goal in mind: take back the city of Manc from the demons who control it, the Halfas family. But the daughters of said family ended up being a lot cuter than he expected...