Bruno, is the son of strict commander of a Nazi concentration camp. He has a strong headed sister, Gretel. They live in a five storey mansion, but are one day suddenly moved to a place called Out-With (Auschwitz).
Bruno, outraged by his father's decision to move to Out-With, and desperate to go home, spends his time in his room with no friends.
He is also annoyed by the fact that they live in a three story house instead of their old five-story mansion, and with such a small space, there isn't any room for exploration (a hobby of Bruno's) to be done.
He also misses sliding down the banister in their old house. From his bedroom window, Bruno spots a fence with people in striped pyjamas behind it.
These are the Jews, and they are in a concentration camp. One day his parents come to an agreement that both Bruno and Gretel need a tutor for their education so they hire Herr Liszt.
To Bruno, Herr Liszt is the most boring teacher one could ever have - because he teaches science instead of the arts, which Bruno prefers.
So, in boredom and confusion he wonders what is going on at Out-With and why people are always dressed in striped pajamas there.