마이니치 방송
The novels were written by Taro Achi, with illustrations by Yu Yagami. The novels were adapted into a three-volume manga series with the same name, by the same authors and published by Dengeki Bunko, and an anime series, directed by Hitoyuki Matsui and Takuya Nonaka, produced by Ufotable, and aired by Mainichi Broadcasting System.