In this game the main character decides to get away from it all during his spring break and stay in the mountains. While staying in the mountains a massive storm causes the main character to faint. A mysterious woman saves him and uses sexual pleasure to keep him warm. It turns out that he is now in a strange old mansion. The woman who saved the main character is the mistress in charge of the place. The main character decides to explore and while there meets many women as the story unfolds...
Dark Illusions is a western remake of "Nocturnal Illusion" in RPG Maker for PS1. The game adds adventure game elements, like puzzles and obstacle courses, removes the presence of Kusayama and adds additional secret characters, one of them being Priss from developer's first game "Treasure Hunters".