Rocca is eleven years old and currently lives with her grumpy grandmother in Hamburg. Her mother died in childbirth and her father set off on a long space mission as an astronaut. When the grandmother has to go to hospital after an accident, Rocca is forced to take care of herself - no problem at all for the clever and bright girl.
She finds good friends in the squirrel Klitschko and the homeless Caspar. But at school she doesn't just make friends with her unconventional nature. Rocca won't let this get her down though. Without fear she confronts sceptical teachers and mobbing classmates, because she is convinced that one can make the world a better place with a big heart.