The film is loosely based on a true story about Paolo Roberto, later a professional boxer and TV presenter. Because of his Italian roots, Paolo is dealing with an identity crisis. With an admiration of kung fu films and with his teenage aggressions, the kung fu films have a negative impact on him, which tempts him to practice violence on innocent citizens in Stockholm.
The films takes place in Kungsträdgården, which normally is a popular meeting place, but is shown differently in the film because it has been occupied by violent teenage gangs. The film was shown amongst students during the late 1980s in order to prevent future violence between rival gangs. However, the film had an opposite effect on the youth who identified with Roberto, and became influential on the violent "kickers" subculture. It is today regarded as one of the most important cult films in Sweden.