At the behest of his father, the young Karl Valentin is to complete a carpentry apprenticeship. When the father gets into a financial mess by a strict creditor, the boy works with growing success as a comedian to support his parents financiall
Mommsen Gymnasium director Taft secretly places his nephew as a spy with the difficult class of Pepe Nietnagel. During the celebration for the 100th anniversary, a simulated fire forces the school to shut down for a week. The director's attempt to get a tough teacher assigned by the department of education results in the exact opposite because of Nietnagel's intervention.
Pepe Notnagel (who inexplicably had his name changed from the first movie's Nietnagel) and his classmates scheme to get around doing any actual school work by cheating or sending their teachers to the sanatorium. A Swiss documentary film maker disguises himself as his brother in law, who got a position as an exchange teacher, to aid his project of making a movie about the current youth.
Pepe Nietnagel and his fellow students of the Mommsen school come up with all kinds of ideas to get out of doing any actual school work. This includes simulating suicides, setting off the air-raid sirens and abusing the school director's new broadcasting system. They succeed in sending their teacher to a sanatorium and get a replacement that turns out to not be so bad after all.
The 13-year-old Ludwig is to have for every joke. At boarding school he cuts his stern teacher, Captain a. D. Semmelmaier, during the nap from the beard. The angry pedagogue then sends the spoiled flail back to his beloved Bavarian village. The long-suffering mother persuades the rector to resume her reforming boy at the Latin school. Everything seems to be working out for the better, but the upcoming marriage of his sister Ännchen with the Berlin beer brewer Karl Schultheiss presents Ludwig with new challenges.