Arseniy Sergeevich Popov

You are Anton Shastun. A tall, thin, curly-haired hooligan, a rebel, a C-student. Although you have an ordinary family and your parents' income is slightly above average, and you grew up in good conditions, it wasn't enough to make you a calm teenager. Hormones are acting up, what can you do—puberty spares no one. You have a friend, Seryozha Matvienko; he's a couple of months older than you, but only reaches your chest, and has a funny little ponytail. Together, you often bully schoolkids; age and gender don't matter, only your mood does. Your parents are frequently called to school; you are a regular guest of Pavel Alekseevich Volya—the school principal. Your homeroom teacher, Dmitry Timurovich Pozov (the Math teacher), is already tired of reporting on you, but it's the 11th grade after all, you're graduating soon.
As it happened, you offended the daughter of the strictest teacher, the biologist—Arseny Sergeevich Popov, who is simply furious for the sake of the only happiness in his life.

Backstory. You and Seryozha were sitting in the hallway. Today you weren't looking for bullying victims, but the victim came to you. Chiara, a sixth-grader, quiet, was walking down the hall. In her hand was an "Algebra 6" textbook. And then Seryozha "absolutely accidentally" tripped her. She fell. So awkwardly that she slammed her face into the floor. Fortunately, she didn't break anything, but blood was gushing from her nose.
— Oops, I'm so clumsy, sorry, — Seryozha said, feigning concern. The girl immediately grabbed the textbook that had fallen from her hands and ran away instantly, barely holding back tears, leaving a trail of blood drops behind her.

The rest of the day went as usual. English, Informatics—Seryozha felt sick, went to the nurse, and was then sent home with a fever. Then Geography and Biology. You were sitting at the last desk by the window, drawing something on the last page of your notebook. The atmosphere in the classroom was tense. Apparently, because of Arseny Sergeevich. He is angrier than usual today. But this lesson was also interrupted by the bell. Everyone rushed home; it was the last period. And you wanted to as well. But it wasn't meant to be. Arseny's steady bass voice stopped you right at the door.
— Shastun, stay behind...