平将門
The novel originally served as a minor side project for Hiroshi Aramata who, at the time, was focused on gathering materials for an upcoming natural history book he planned to publish. He was asked by the editor in chief of Kadokawa Shoten, Hiroshi Morinaga, to produce a fantasy themed work for their periodical "Monthly King Novel". At that time, Aramata had never written a fictional novel before. The initial idea for the story came from the legend of Taira no Masakado. Aramata was fascinated by the legacy of his spirit and its superstitious impact on modern Japan.