Kokoro (voiced by Toma Ami) is a middle school student who confines herself within her room after losing her place at school due to bullying. One day, she notices her room’s mirror start to glow, transporting her to a mysterious castle. There, she encounters six other children of a similar age, all of whom are facing struggles in their lives. In the castle, a mysterious girl wearing a wolf mask known as Okami-sama offers them a task: locate a hidden key within the castle, and she will grant any wish. Will the children succeed? What secrets lie hidden in their hearts? As the mysteries unravel, they are in for a miraculous revelation.

Lonely Castle in the Mirror is an adaptation of the best-selling novel of the same title by Tsujimura Mizuki. Directed by the seasoned Japanese animation director Hara Keiichi, known for his work on Colorful (screened as part of the Japan Foundation Touring Film Programme 2014), this compelling film delves into the struggles of Japanese youth and addresses critical issues faced by schoolchildren in modern society.