A guy and a gal stuck in dungeon need to escape. But to get out the gal needs to stay virgin otherwise the final door will stay locked forcing you to start new game +. For that to happen the players needs to keep her perversion under control otherwise she will initiate sex herself. Not sure about this but they died or something? Also not sure about this but they might have been siblings. You could just play as its suppose to be played to win or willingly sabotage the whole thing by fondling her and going into traps in the dungeon.