These bullying mangas really make Japan seem like it's the fucking Wild West
You hear less about it now, but I still remember that time a suicide at a school (in Japan, of course) led a vigilante to travel across the country to attack the principal of the school with a hammer. This was... fuck, i want to say 2012? It was ages ago. Haven't thought about it in a while, so my memory of the news are fuzzy. The bullying the victim went through was fucking harsh. There's some horror stories out there, man.
You can probably find stuff from other countries too. French teachers get bullied because teaching is seen as a lowly job in France, slavs being their own worst enemy, american shooting galleries, british teachers of old acting like devils (Roald Dahl had a couple of stories about his experiences going to school), so on and so forth. If you're willing, the information is out there.