Lonely Castle in the Mirror

Kokoro Anzai, a first-year student at Yukishina Junior High School, struggles with bullying and decides to avoid attending school altogether. She feels increasingly uncomfortable in her environment, leading her to seek refuge away from her classmates.

One day, while in her room, Kokoro discovers a magical portal hidden within her mirror. Curiosity gets the better of her, and she inspects the mirror closely, only to find herself unexpectedly dragged into another realm.

Kokoro emerges in front of a mysterious castle situated on an isolated island. She is greeted by the Wolf Queen, who appears wearing a wolf mask. The Wolf Queen introduces Kokoro to six other children who are also finding solace from their troubles.

The Wolf Queen explains that they must locate a hidden key in the castle before a looming deadline of March 30 of the following year. Should they find the key, they can make a wish, but failure means the children will be forgotten.

The seven children start to bond and spend time together, exploring the castle and searching for the elusive key. They share their experiences of bullying and avoidance, discovering that they all attend the same school but seem to exist in separate realities.

As they meet at school, they realize they do not recognize one another, leading Masamune to theorize that they might be from parallel universes. However, the Wolf Queen disagrees and asserts that they are in the same realm.

With the deadline approaching and still no key found, Kokoro opens up to her mother about the bullying, seeking help from teachers. Each child begins to confront their fears and challenges, pushing for resolution in their lives.

On the second to last day before the deadline, Kokoro stumbles upon an illustration titled 'The Wolf and the Seven Young Goats', realizing it holds the clue needed to find the key. This discovery reignites their hope and determination.

Upon returning home, Kokoro finds that the mirror has shattered, leaving her anxious. The group learns that Aki, one of their friends, stayed past the crucial time and was eaten by the wolf, which leads to a grim sense of responsibility for the group.

Determined to save her friends, Kokoro traverses the remnants of the broken mirror and uses insights gained from the illustration to find the long-sought key. In an emotional journey, she also confronts the painful memories of her friends.

Kokoro uses her wish selflessly to resurrect her friends, demonstrating her growth and newfound bravery. Aki reconciles with the group, highlighting the importance of friendship and support in overcoming adversity.

Before they must leave the castle forever, the children realize they are indeed from the same universe but exist across different timelines that span over 40 years. They engrave their names on the castle wall as a symbol of their shared experiences.

After bidding farewell to one another, Rion confronts the Wolf Queen, who reveals her true identity as his late sister, Mio. Their reunion is bittersweet as she takes off her mask, imparting one final farewell before he returns to his own timeline.

Kokoro finds herself back in her own world and reunites with Rion. As they make their way to school together, it symbolizes a new beginning for both, free from the haunting memories of their past pains.