@Kirin-kun You are correct that I do not know the experiences of a 14- year- old growing up in Japan. You are correct that it has almost certainly had an effect on her personality.
The problem is that even if all of that is true, that still does not justify her hatred of all males. If this were a heterosexual 14-year-old being hateful of the opposite or the same gender, then it would be completely normal to criticize that person.
We literally have seen her back story already. Nothing within that gives her reason to be so hateful of all men. Yes, IF new facts emerge that make her understandable, then I would change my mind. However, until that time, we are left with this character who is hateful without a good reason. At this time, she really has no excuse.