Petunia Perry has decided to write her memoirs. She wants the world to know what it's like to start secondary school with a best friend who stages one-person flash mobs in the canteen, a mother who over-shares at parents' evenings and an unwelcome suitor who draws pictures of her as a unicorn. But it's when she decides to start a band with a spoon-player and a lead-singer who's a cat that things take a turn for the truly crazy...