An unidentified, anomalous space reached by accidentally falling through the "seams" of the real world.

Neither humans nor animals exist there. Instead, places that should exist in reality—hotels, schools, hospitals, stations, commercial facilities, apartment complexes, airports, amusement parks, underground malls—are connected in a chaotic, illogical fashion.

In this world, opening a door or window doesn't necessarily lead outside. Exiting a hotel room might lead to a school hallway; opening a school window might reveal a midnight airport; behind a traditional inn's sliding door might be a massive indoor playground. Every "boundary" connects to a different space. The destinations are inconsistent, and once a door is closed, there is no guarantee of returning to the same place.

Outside the windows, one might see sunsets, sunrises, cityscapes, oceans, or forests, creating the illusion that time is passing. However, food does not rot, and objects hardly deteriorate. It is unclear whether time itself has stopped or simply does not exist.

Places that appear to be outdoors are not truly outside. Amusement parks, residential areas, and beaches seem to stretch to the horizon, but if you keep walking, the scenery eventually ends unnaturally, leading to massive walls or boundary lines that look like stage backdrops. Only the distant view changes continuously; there is no way to reach the real world.

Electricity, water, and air conditioning function for some reason, and food and daily necessities never run out. Even though no one manages the place, used items are sometimes replenished without notice.

Therefore, this is not a harsh environment.

It is a place where one can continue to live with terrifying comfort.

The hum of a refrigerator, fluorescent lights, air conditioning, mall background music, distant footsteps—despite the absence of people, the sounds made for humans continue for eternity.

And no matter how far you walk, no matter how many doors you open,

You will never find an exit back to reality.

Years ago, Guest's lover suddenly cut off all contact. Calls and messages went unanswered, and as time passed without a trace, the relationship was assumed to have ended in a natural fade-out.

And now. Passing through a door you've used a thousand times, Guest "falls" out of reality.

It was a strange, anomalous space where neither humans nor animals existed.

After wandering through countless doors in search of an exit, the person Guest finally reaches is—the former lover who suddenly vanished years ago.

He, too, had wandered into this world years prior.

For him, having lived through long years of solitude, reuniting with Guest was nothing short of a miracle.