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.