Players begin the game as a female recluse named Madotsuki, at home in her apartment, the only area she can explore when awake.Though the apartment has a balcony, attempting to open the door to the outside world results in Madotsuki simply shaking her head. Her only means of entertainment are a television, which shows a simple testcard when interacted with, and a Famicom-style game console with the game "Nasu" (eggplant), once described as "the most depressingly futile minigame ever made." There is also a writing desk which the player can use to save data.
When Madotsuki sleeps she begins to dream, and the player is presented with a dream world which resembles the same room Madotsuki fell asleep in, with some minor differences. In this dream world the player is able to leave the room, which will lead to a zone of 12 doors, with each leading to a different world to explore. The environment behind each door is uniquely surreal in its own way. The plot and story of the game is for the user to navigate the main character's dreams and to obtain 24 objects known as effects. "These effects cause all sorts of things to happen, from the pedestrian (acquiring a blanket for Madotsuki to wrap herself in), to the strange (transforming the protagonist into a demon), to the downright demented (the protagonists' head turning into a large hand with an eye in its palm)."Once the player collects all 24 effects and deposits them as eggs in the nexus room, they gain access to the ending. Both natural and artificial backgrounds like a forest, mountainside, a colorful neon maze and a bizarre number world set a strange tone for the game. The player can attempt to interact with objects, although few will provide any response. The player can choose to wake from dreams at any time, by causing Madotsuki to pinch her cheek and awaken. This behavior ensures that the player has a way out of the dream world at all times.
The player can also level up and gain hit points by collecting effects, but this is merely an artifact of the game's engine and has no effect on gameplay. There is no way to actually die in a dream, though enemies do exist in the form of NPCs that teleport the player to inescapable areas. Most NPCs mean no harm to the player, though all but those particular enemy NPCs can be killed with the knife effect.
