9 "A" was an exemplary class, while their class teacher was Nosov Anatoly Germanovich - a strong and experienced teacher, recognized in 2009 as the Teacher of the Year. After his sudden illness, 9 "A" is left without a strong hand. The myth of the exemplary class is crumbling, discipline is cracking at the seams. Nosov's granddaughter, Anya Nosova, is perhaps the most difficult teenager of the school. A new student Ilya Epifanov provokes situations in which students manifest themselves from unexpected sides, turning upside down the usual idea of them as classmates and teachers. None of the teachers want to take on the class, which of the model has become the most difficult.