40 chapters deep and these kids still have it out for Nishimura.
It's starting to get sad, and maybe a little suspicious. Why would they be so hard up on ostracizing just one girl? There has to be a reason for it for them to latch on so feverishly.
I guess "it's the crux of the plot" is a simple, blanket answer. But it does get the mind going on the conspiracy behind it.