Mia tries to make friends with Olivia, the new girl, but when Olivia makes fun of the other Cupcake Club girls and tells Mia she shouldn't hang out with them, Mia must make a decision about her new friendship.

For as long as Katie can remember, it's just been her and her mom. But that's about to change. First her mom gets a boyfriend. And then Katie gets an email from her dad, whom she's never met, saying he wants to get together. Katie's not sure she's ready for so much change in her life. With so much happening at once, Katie's counting on her friends in the Cupcake Club to help her find the sweet side of what seems like a sticky situation.

"Alexis is the clear leader of the Cupcake Club: She's organized, punctual, and happy to take on the stuff like scheduling, budgets, invoicing, and the things that the other girls don't really want to do. In other words, the "unfun" things. But one day Alexis feels particularly unappreciated and informs the Cupcake Club that she is no longer in charge! After deadlines get missed and supplies aren't bought, the girls realize they definitely need a...

Emma's younger brother Jake has tonsilitis and makes life difficult for Emma, while the Cupcake Club girls are spoiling him with cupcakes and little gifts.

Although Mia feels fairly satisfied with her life, she worries about who should attend parent-teacher night and her failing grade in Spanish.

When Mia arrives at her new school, her goal is to be open to and friendly with everyone, but everyone at Park Street School fits into a clique. When the Popular Girls Club takes an interest in Mia's awesome fashion style and wants to recruit her, Mia must decide between them and her great new Cupcake Club friends. It's like choosing between her divorced mom and dad and her old house and new house. Is it always going to be Mia in the middle, or can...

When Alexis develops a crush on Emma's brother, she decides to approach this new feeling in her usual organized manner by conducting research and developing a plan.