After her father dies, Mackie and her mom move to a new town. As she makes new friends, she discovers a band she wants to join. The only problem is, the band consists of only boys and no girls are allowed. She comes up with the idea to dress like a boy to join the band and be part of "The Challengers". Balancing out between dressing up as a guy in the band and a being normal girl with her best friend Jenny is harder than she thought.