The story is about a witch named April with the power to turn lies into reality. Due to this terrifying power, April is confined in a small house. However, once a year on April 1, April opens the door to her house to visitors. (Source: Tsuki-kan)

Shigatsu no Majo no Heya was originally released on TYPE-MOON's homepage for a limited time as a part of an April Fools' Day project. It was officially published by Seikaisha under the Seikaisha Fictions label as a boxed release, including a full-color hardcover version of the novel and an audio CD with the story narrated by Maaya Sakamoto.