Rosie and Penn always wanted a daughter. Four sons later, they decide to try one last time – and their beautiful little boy Claude is born. Life continues happily for this big, loving family until the day when Claude says that, when he grows up, he wants to be a girl. As far as Rosie and Penn are concerned, bright, funny and wonderful Claude can be whoever he or she wants. But as problems begin at school and in the community, the family faces a seemingly impossible dilemma: should Claude change, or should they and Claude try to change the world?