Wow. WOW.
Ok, they are all teenagers, but the 'mean girls' clique accepting the MC and turning on Ichika that fast was really disconcerting. And none of her 'friends' tried checking up on Ichika when she hadn't shown up for two weeks straight? Those are not 'friends' the MC should want to have. (They're probably what she deserves after what she did, though.)
I think the real tragedy here is that the MC and Ichika utterly failed to realize how similar they are, and got set in opposition to each other over a pretty dumb misunderstanding. Poor Baseball Guy (currently the only character in this manga I'd categorize as unambiguously good - Bike Dude set up a gang rape) is caught between two girls who are arguably broken or on the edge of breaking, and fully willing to break others.
If the flash-forward in the first chapter was any indication, he's going to break too. I'm honestly having trouble caring about these people just endlessly hurting each other.