is a Japanese online novel by Natural-Rain. It was originally posted online in 2004, and was published in June 2012 by East Press. An anime television series adaptation by Drop aired from July 12 to September 27, 2017. The series is entirely directed and animated by Naoya Ishikawa. Characters Media Anime An anime television series adaptation by Drop aired from July 12 to September 27, 2017. The series is entirely directed and animated by Naoya Ishikawa. The opening theme is and the ending theme is , both performed by former SKE48 member Aki Deguchi. It was streamed exclusively on Amazon Prime Video. Notes References External links 2017 anime television series debuts 2012 Japanese novels Anime and manga based on novels