When Posey's first grade class gets a new student, she worries her friends will like the new girl more than her. Posey and her best friends, Nikki and Ava, do everything together. Then, new girl Grace joins Miss Lee's first grade class, and Posey worries that everything will change. Nikki and Ava can't stop talking about Grace's long princess hair, and when she joins the girls' recess games, they like her way of doing things better than Posey's. But when Grace accidentally teases Posey, she's had enough: she doesn't want to play with Grace ever again! Can Posey's princess tutu help her find a way to get along with the new student?