Long ago, a monk named Myoue had the ability to bring anything he drew to life. He lived peacefully with his wife, Koto, a black rabbit transformed into a human, and their three children: Yakushimaru, Kurama, and Yase. But the local high priest considered Myoue's creations a disturbance to the community and insisted he take action. To avoid conflict, the family secretly escaped to a parallel world Myoue had created: the Looking Glass City.
At first, the new world was peaceful, until Myoue and Koto vanished without a trace, leaving their three children to govern the city. Yakushimaru took on his father's duties and responsibilities. They remain trapped in this alternate reality, and their troubles grow when a young girl named Koto suddenly falls from the sky. She claims to be searching for the missing Myoue and Koto as well. Armed with a massive hammer and accompanied by two mischievous familiars, this newcomer might hold the answer to freeing everyone from the endless confines of the paper city.