I dont think the boys wanna get back at the girls for any reason, I feel like they just get a kick out of messing with them.
And the teacher gets nervous around the girls she teaches too, so I don't see how an encounter with those boys would be any less frightening
Well, there's another side for every story. Maybe they really mess with the girl with no reason, and maybe they have a reason. Just like there are reason for the girls to be frightened or annoyed with the boys harassment.
But, just like how the teacher at Kikyou wanted the boys to understand them, the Chidori's side need understanding as well.
Instead, the adults fed on their anxiousness and blame the boys.
It just sad when Rintaro gave his story and said "no one would care about the reason why he choose to dye his hair and dress delinquently,"
And how he's the one had to change to made others comfortable.
Maybe it's the price living in the society where becoming different is a bad thing.
I kinda understand how Chidori students kinda want to mess with the girls.
They almost daily get these girls frightened just by look at them. And in the flashback, they literally just greet the teacher but she's got scared. I'd get pissed off too.