A girl begins to dream. Finding herself in a room much like her own, she discovers a nexus of doors leading to many different places. Some of these dreamscapes are pleasant, while others quickly turn into nightmares. Collecting objects known as "Effects" to get to new places, she continues to wander aimlessly through the dream world. When each dream ends, she writes the events in a diary, and soon drifts off to sleep once more.

As she tries to understand the meaning behind these dreams, this girl soon discovers that she may not be alone, as someone is watching her and her dreams closely.

[Written by MAL Rewrite]