Seven students in a peaceful Tokyo neighborhood are avoiding school by hiding in their bedrooms and isolating themselves from loved ones. However, their lives change when they discover that the mirrors in their rooms shine bright with a single touch. The touch pulls them into a castle that seems to be straight out of a Grimm's fairy tale. Although lacking in food and running water, the castle has numerous electrical sockets and is ruled by an irritable girl named Wolf Queen who wears a mask. This castle becomes their sanctuary during school hours. While there, they learn that there is a key that will grant one wish, and they must decipher clues to find it before the school year ends. The catch is that they must leave the castle by five pm every day, or else face dire consequences. As time passes, they realize that only those who are willing to open up and share their stories will be saved. They begin to unlock each other's stories and struggles, like a boy who is showered with gadgets but not love, another who has faced rejection without explanation, and a girl who fears her predatory stepfather. As they follow the rules of the game, they realize that they are trapped in a cycle of misunderstanding and loneliness. This realization leads to a touching story of friendship, empathy, and sacrifice, where they ultimately set one another free.