The main character is the Windup Girl. Then there are the power - hungry businessmen who see her as a tool for their own gains. There are also some local Thai people who are trying to preserve their way of life in the face of this new technology. Each character has their own motives and goals which drive the story forward. For example, the Windup Girl is trying to find her place in a world that doesn't really accept her, while the businessmen are more interested in exploiting the technology behind her creation for profit.
The Windup Girl is the central figure. Besides her, there are various characters representing different aspects of this future society. There are the corrupt politicians who want to control the new bio - technology for their own political ends. There are also some scientists who are involved in the creation and study of the Windup Girl and other bio - engineered beings. These characters interact in a complex web of relationships that form the backbone of the story in 'the windup girl novel'.