If you didn't want him getting close to you, why did you approach him in the first place!? You're the one who invited him to your party in the beginners dungeon, and you're the one who kept approaching him during class. Seriously, what's wrong with you, woman?
This seems dumb, but remember how they handled the teacher's plot, having the student president, the principal and the mom involved to solve the case. This seems like another over-the-top edgy bullying plot yet again, but execution is key and so far this manga has been good with how it handles these usually cliché bullying moments.
Also, I would like to say I have seen my fair share of women that keep attracting men and then complain that men won't stop coming onto them. It's like they have an uncontrollable urge to seduce someone and can't turn it off when they want to be alone, but instead of understanding that it's their problem, they throw the responsibility onto someone else.
I had this happen to me in high school, when a friend of our classmate (both girls) came to our school one day and kept flirting with me, touching me and asking if I went to the gym(which I clearly didn't and no one could reasonably think otherwise), trying to hold my hand (which I didn't reciprocate and had my hand closed but she kept holding it nonetheless) and other stuff that made me uncomfortable. To make matters worse, she had a boyfriend and everyone there knew it.
You know what she did after we all left school and went our separate ways? She told our classmate that I was coming onto her! Obviously our classmate saw the entire thing and didn't buy her bullshit for even a second, but that goes to show bitches be crazy, and the character this chapter portrays is over-the-top, but not unrealistic!