Shy outcast Kokoro has been avoiding school for weeks when she discovers a portal in her bedroom mirror. She reaches through and finds herself transported to an enchanting castle where she is joined by six other students. When a girl in a wolf mask explains that they have been invited to play a game, the teens must work together to uncover the mysterious connection that unites them. However, anyone who breaks the rules will be eaten by a wolf.

The forbidden book that will make any wish come true "The Ghostly Book of Books". However, in order to make your wish come true you have to go through a life-threatening trial. What is that trial...?