Man, I don't know where this manga is going and it's making me incredibly nervous.
On one hand, it's a manga featuring horrible bullying, but on another it could be restricted to just the beginning so they can establish characters and show how much they've changed.
Then again, it's common for manga plots to show an incredibly heartwarming situation/state of things before stabbing you in the heart with a suprise gory death of a 'good' character'.
But it could also just want to show unlikely friends overcoming their differences and challenges together (I don't even feel bad for the pedo blackmail/rapist teacher, a victory for friendship, justice and all good in the world if you ask me).
Aaaaargh please - if you're going to tear out my heart do it now before I start hoping!