Sullen middle school freshman Kokoro (Ami Touma), is frightened to attend school after getting bullied by her aggressive female peers. Any reminder of school leaves her with a stomachache as constant anxiety washes over, preventing her from getting out of bed. Who can blame her when the bullying is so intense? Girls at her school either tell her to drop dead or stalk her back home, where they attempt to trespass. For the growing teen, staying home is the most viable option.

Bedridden in her room, Kokoro finds a portal inside her full-length body mirror. She steps through to the other side, transporting her to a magical castle straight out of a fairy tale book. There, Kokoro meets six other teenagers around her age. They sit on a staircase, awaiting information about their random invitation.

The Wolf Queen (Mana Ashida), a tough, commanding little girl in a wolf mask, appears. She tells them they have been selected to play a game. They all have about a year to find a key lying about in the castle. Whoever finds the key is awarded a wish. But if anyone breaks a rule, that person gets eaten by a wolf as a death sentence. Throughout the year, Kokoro and her peers try living their double lives freely, taking school one day at a time and reuniting at the castle afterward.

Based on the novel of the same name by Japanese writer Mizuki Tsujimura, this animated adaptation of Lonely Castle in the Mirror wears its good intentions on its sleeve. Its fantasy and realism elements hold stable ground and offer a mature observation about teenagehood’s hardships, including the cruelty teens face at school or home and the deep loneliness that stems from such rooted trauma. 

A few months deep into visiting the lonely castle, Kokomo learns that, like her, each teenager has little to no control over their life or surroundings. But the longer time spent there, the more it looks like a peer-led recovery group offering solace and safety than it does an enchanted castle. When the film details the other issues everyone besides Kokoro holds, it wavers from plain sad to horrifying.

The decent animation by A1-Pictures (“Fairy Tail,” “Sword Art Online”) offers unique background landscapes, several 3D shots, and an attention to scale when the teens are against the massive castle halls. But despite those positives, there’s hardly any justification for its overall presentation. Compared to “Fairy Tail” and the many “Sword Art Online” features, “Lonely Castle” is a more laid-back dramatic offering than other A1-Pictures features that often bear vibrant flashiness. Regardless of the genre and tone, “Lonely Castle” desperately needed some glitz. 

In fantasy-coming-of-age stories of similar tone and maturity, like “Chronicles of Narnia” or “Bridge to Terabithia,” a refreshing gust of whimsy capturing youthful joy can balance the bleakness of the mundane. And yet director Keiichi Hara misses the potential to add an elegant factor that would give the film weight. The only convenient time the animation is astonishing is around the climax, which is already late. 

The teenage ensemble all are likable enough. But they severely lack personality and complexity beyond their traumatic backgrounds, preventing them from feeling like a natural friend group. Their shared camaraderie is weak, especially since their dialogue is basic conversations that play to the stereotypical anime archetypes—the quiet type, the confident older sibling type, the nerdy type, the mysterious type, the aggressive type, and the goofball romantic—and their only activity is working together to find a key. But as time passes, the relationship shared between Kokoro and her fellow teen outcasts barely progresses.