Nocturnal Illusion

While spending his spring break in the mountains, Shinichi faints during a storm after falling down a cliff and is saved by a woman who keeps him warm (with her body heat). He wakes up to find that he's stuck in a mansion that is separate from regular time and space with a gate that only opens when it chooses. The woman who saved him, just known as Mistress, is in charge of the place. During the game the main character can meet and have relationships with the women he meets. At the end, the gate opens and the main character can decide whether or not to take one woman of his choice with him.

Nocturnal Illusion is a Visual Novel released in 1995 (in Japan) and 1997 (in the United States). It was given a renewal in 1998 with cleaner graphics. The game fell into abandonware and is freely downloaded for free, with an English translation. Information on where to get the game can be found here.

A trilogy of books based on the visual novel were written by Jack Bushell.

Needs Wiki Magic Love.

Tropes:

 * Adult Child: Misao, who's eighteen-years-old in the English version.
 * Attempted Rape:.
 * Blood Splattered Innocents
 * Bondage Is Bad:  It's worse when you realize that it's been done to her so much that she developed a Pavlovian response to such acts, unable to feel pleasure without being subjugated to some form of bondage.
 * Brainwashed and Crazy
 * Closed Circle
 * Cute Ghost Girl: Sari
 * Creepy Basement
 * Creepy Doll
 * Curtains Match the Window: Most of the characters.
 * Dark Is Not Evil
 * Defrosting Ice Queen: Maya is condescending toward Shinichi early in the beginning. She softened up alot after getting to know him better.
 * Dramatic Wind
 * Driven to Suicide:
 * Does Not Like Men: Maya, due to many men looking down on her just and saying she should become a housewife.
 * Everybody Calls Her Mistress
 * Freudian Slip
 * Girl On Girl Is Hot
 * Healing Potion
 * Hearing Voices
 * Hello Insert Name Here: It is possible to change Shinichi's name.
 * I Choose to Stay: A few endings can end in this way.
 * Inner Monologue
 * Innocent Fanservice Girl
 * Intimate Healing
 * Involuntary Shapeshifting: Sari turns into a flower in the day.
 * I Will Wait for You
 * Kick the Son of A Bitch
 * Kiss of the Vampire
 * Littlest Cancer Patient
 * Leitmotif
 * Love Triangle: Mermaid was in one of these with her prince. She loved him but he loved somebody else. Due to the witch's curse on her, she was to become seafoam
 * Mermaid Problem
 * Multiple Endings: All of them depending on the girl picked at the end. Only two endings are affected by past choices.
 * Nothing Is Scarier: Getting to the front gate right after you start exploring yields a suprisingly unsettling one.
 * Older Than She Looks: Arisa and Miwako.
 * Our Vampires Are Different:  needs blood to survive, which isn´t too odd. However,   to avoid contact with the sun.
 * Purple Prose
 * Scare Chord
 * Secret Underground Passage
 * Spooky Silent Library
 * Sword of Plot Advancement
 * Tap On the Head: Kusayama gets it once.
 * The Alcoholic: Kusayama.
 * Time Skip
 * Tomboy: Misao
 * Vagueness Is Coming
 * Waking Up Elsewhere
 * White Haired Pretty Girl: Sari
 * You Gotta Have Blue Hair