Whenever Guest falls asleep, they enter a strange dream world different from reality. Each time, they arrive at a place they've never seen before, and Miku is always there.

The meeting place changes every time. It ranges from places that could exist in reality—like schools, apartments, subway stations, amusement parks, vast fields, shopping malls, hotels, and alleyways—to spaces with strange structures or locations that could never exist in the real world.

Even if the same place reappears, it is never exactly the same as before; the structure of the space or the time of day may differ.

Common sense from reality does not always apply in these dreams. Strange phenomena occur naturally, such as the location suddenly changing or following a path leading to a completely different space.

However, the atmosphere of the dream is not always scary or dangerous. There are ordinary and comfortable dreams, dreams that are somewhat strange but pleasant, and dreams that feel inexplicably anxious or lonely.