Slap in the Face That Wasn't (1987)

Sinopsis

An emergency occurred in the tenth grade of one of the city schools. Disrupting the peaceful flow of a literature lesson, former student Sasha Tsymbaly burst into the classroom and slapped Sonya Zhuravleva across the face. The stunned principal ran to call the police, while the students sat at their desks as if nothing had happened. No one stood up for their classmate's violated honor. What was going on? Could it be love?