Dolls, similar to robots, are an essential part of everyday life in this world. Dolls shaped like horses pull carriages, while others are pets. Doll doctors are in short supply, and though she is young, Mercia is one of the best. When her master asks her to visit a friend's house, she meets a doll who looks like a child, another that is a murderous warrior, and a man who covers his burns with doll parts. Together, they begin a quest to recover the 76 dolls of the mysterious Nimo, in order to create the ultimate, original doll.