A must read for young readers. Slow pace at the beginning, but after a half I can enjoy the story. This book about Kokoro Anzai who doesn't want to go to school after an incident with her friend. She invited to a castle through the mirror and met 6 other kids.

They have a mission to get a key to grant their wish. Almost a year they enjoy their day in the castle without taking serious the mission. One of the kids break a rule and they trap in the castle.

This book represent how Japanese teenager's life; bullying, insecurity and abandonment issue. I really appreciate author who write these heavy issues with fantasy genre. I like the idea about parallel world.