"It is not just "bullying."
Nakajima was ruling over the class as a bully. The subject of bullying is a fragile girl called Shirasaki-san. Going as far as violence, every day was horrible. Everyone in the class pretends to not see it. If they try to stop him, then they will be the next target. Nakajima engages in bullying as if possessed. It was clear that something was wrong. Why does he do such brutal acts? The truth was terrible...