The almost 14-year-old Seppi is back! After his personal "enemy" Schacke-Line kissed him against his will during the Christmas play, he wanted to take his time to prepare for his revenge. But he has no time for that, as a new student is challenging his position: Kevin! And he becomes instantly popular with everyone. Only Seppi and his best friend Hansi see through him. Both start the "Operation Idiot Defense" and take on the battle against annoying classmates, irritating teachers, and demanding mothers.