Vahetuslaps - Christine Nöstlinger

An exchange student from England comes to the Mittermeiers, a family living in Vienna, to improve their children's English skills. Instead of the originally supposed to arrive, the very neat Tom, his brother Jasper is sent instead, who causes a lot of confusion with his unusual behavior. The eventful six weeks of the summer school vacation are described in the form of a diary by the 13-year-old son of the family, Ewald. During this time, Jasper manages to turn the Mittermeiers' previously neat and boring family life upside down, and he also irrevocably changes the relationships between the family members... However, the exchange student, who was a scourge at first, eventually comes to love the whole family.