Lonely Castle in the Mirror

is a Japanese novel written by Mizuki Tsujimura, and published by Poplar Publishing in May 2017. A manga adaptation illustrated by Tomo Taketomi was serialized in Shueisha's seinen magazine Ultra Jump from June 2019 to February 2022, with its chapters collected into five tankōbon volumes. An anime film adaptation by A-1 Pictures premiered on December 23, 2022 in Japan. Characters Media Novel Written by Mizuki Tsujimura, Lonely Castle in the Mirror was originally published on May 11, 2017 through Poplar Publishing. The company re-released the novel in a two-volume paperback format in March 2021. The novel was published in English by Doubleday in April 2021.