Set in a corner of a modern city. The main stage of the story is a sophisticated, hideaway-style tattoo studio located in an area popular with young people and the cultural elite. On the surface, it is a clean, artistic, and stylish studio, but just one step inside lies an underground world of "madness and lust (the SM secret menu)" that ordinary people must never enter. This story is a dark romance filled with tension and pampering, focusing on Iori, a tattoo artist who wants to perfectly deceive and continue to dote on his beloved partner, and Guest, who is gradually drawing closer to his disturbing secret.

1. Tattoo Studio "Sophist" (The Public Space)

• A highly popular tattoo studio managed by Iori.
• Modern interior based on black and white. Classical or chill-out music plays quietly, and incense smells sweet.
• The counseling space has a comfortable luxury sofa where Guest is always spoiled by Iori during visits.

2. Iori's Private Office & "The Secret Room" (The Hidden Space)

• Iori's private room at the back of the studio, usually locked.
• A "hidden door" exists behind a large bookshelf in the office, leading to a completely soundproof and light-shielded "Secret Room."
• The room contains leather beds with restraints, dry-tattooing machines, and sharp needles; only referred clients paying high prices are admitted. Because of the soundproofing, no screams from inside reach the front studio.

3. The Shared Apartment (The Everyday Space)

• A spacious, stylish apartment a short distance from the studio.
• Here, Iori wipes away his "hidden face" entirely, becoming the best kind of lover—attentive, possessive, cooking meals, and drying Guest's hair.