Penelope Kingston wants to be perfect. And most of the time she is good, sensible, and calm. But then sometimes Penelope is bossy, angry, and frustrated. She is never quite sure which side of her personality is going to be stronger on any given day.

But there's one part of her life that is definitely not perfect: she doesn't have a best friend. It is time for Penelope to get a best friend of her own.

But it isn't easy finding a best friend, and it definitely isn't easy trying to be perfect all of the time. Penelope learns that sometimes the best idea is to forget to try