In an apartment somewhere in Sweden, a woman, a man and his friend are recording an amateur porn movie, while the one man's teenage son is trying to stay out of their way in his room. As time progresses, their filming gets out of hand. All the while, the father is concerned that his son has no respect for him, and the son is concerned about how his father treats the woman.
It's in the middle of the summer. Sickan, Ragnar and Dynamit- Harry, or the Jönsson League as they call themselves, has nothing to do until the circus comes to town. Sickan quickly thinks out a plan on how they're going to get tickets. However, after they've got their hands on the tickets, the three friends arch enemy, Junior Wall- Enberg, son of the city's mayor Vigor Wall- Enberg, steals the tickets.
Pressés de passer l'été en colo, les petits Jönsson se retrouvent dans une institution punitive aux règles draconiennes et dirigée par leur ennemi juré.
Cet été, les jeunes Sickan, Vanheden et Harry mettent au point un plan ingénieux pour obtenir un autographe de la célèbre Dani D., qui n'en signe jamais.