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.

Um aus dem Internat wieder nach Hause geschickt zu werden, schneidet Ludwig den Bart seines Lehrers Hauptmann a.D. Semmelmaier („Ihr Purschen“) ab, während dieser ein Nickerchen hält. Endlich wieder daheim, bietet die Hochzeit seiner Schwester Ännchen mit dem jungen Karl Schultheiss viele Gelegenheiten für neue Lausbubenstreiche.