The sci-fi alternative period story is set in Tokyo during the Taishō era in 1922, one year before the 1923 Great Kantō earthquake.

A graphic novel serialization relating to the anime is being published in Japanese magazine Animage, beginning from its July 2009 issue. The serialization was re-published as its own book in April 28, 2011 by Tokuma Shoten as a Roman Album.

The story centers around a 12-year-old girl named Ain, who often builds devices despite the lack of scientific background for them, one of her ongoing works is a mysterious robot which she refers to as Father. Ain also created computer monitors able to predict the future, her associate Takeshita, a 30 year-old man, sells these "prophecies", to the Japanese military and the aristocracy to fund for Ain's inventions.

As inspirations in Despera's development, ABe cited on the Despera Blog, The Demon of the Lonely Isle a detective novel by Edogawa Ranpo published in 1930. This book helped him with expressions and illustration of the Taisho era. He also cited books about the particular writing style and women fashion of the Taisho era.