Nine-graders Konstantin 'Tino' Krumov and Boyan 'Bobby' Valchev are returning from a summer break with a plan to start a rock band. Tino is planning to be the solo guitar, while Bobby will be the bass. They set out to recruit additional members at school as soon as the school year begins.
Tino drives his neighbour's jacked jeep to the block where he lives and barely gets away with it (the unsuspecting neighbour just sends regards to Tino's mother and promises to give him the jeep to ride some day, unaware that the boy had just done so). Tino returns home to his little sister Lilly and his mother Maria - and, to his dismay, his mother's obnoxious boyfriend, Peter.
On the morning of the school year's opening at the 197th school in Sofia, physics teacher Nikola Savov wakes up to the sight of a random woman he has slept with, who insists that he repeats the lesson in quantum physics he gave her last night. He declines and "borrows" her husband's jacket to appear properly dressed at the opening ceremony, then he leaves.
Tino, Lilly and Bobby walk to school as the boys discuss recruiting a drummer. They they laugh along the way with Bobby bragging about his conquests and Tino playfully mocking his sister's speech impediment.
Hungover Savov wakes up from a nap at the bus stop, to the amusement of two elderly ladies. Later, at the school opening ceremony, the principal Bogomil Tsekov is nervous as he prepares everyone for the event. He finds out that the P. Ed. teacher, Desislava Marinova, who should organize the parade, is missing. Meanwhile, Savov is in his cabinet's storage room and Marinova enters, and after a brief salute exchange the two start having sex.
At the same time, Tino and Bobby are in the yard as they notice resident delinquent Gencho 'The Ghetto' and his pals trying to mug a boy from the next class, Philip Stoychev and his friend Anny Mateeva. Tino rushes to help, urging Bobby to come along. A brawl ensues right behing Tsekov's back as he gives a speech about how successful and disciplined the school is. To save the day, music teacher Mrs. Kostova signs the school choir to sing the hymn of learning and Bobby, fresh from the fight, starts mock singing behind the headmaster's back, to the amusement of his many fangirls.
Later, Tino and Bobby are called to the principal's office for an interrogation, along with Gencho and his friend Sony Bonanza. Tino and Bobby are automatically declared guilty. Bobby relents and apologizes, while Tino does not and tries to explain that he tried to defend Philip. Due to his prior bad behaviour, none of the teachers even consider believing him and he is punished with probation.
Tino and Bobby walk to class through the hallway, where they see Philip and Anny. Tino stares at her, visibly smitten, but is called aside by his literature teacher. Bobby tries unsuccessfully to flirt with Anny, who is looking at Tino instead. Then he notes how much prettier she's become over the course of the summer.