This teacher reminds me of 2nd grade; I learned differently from the other kids, so the teacher required me to tell the class that I was "Too stupid to understand (insert lesson)" every time I didn't immediately understand her.
Teachers like this were common in my experience.
I think what people are forgetting is that in their world the MC's magic is not understood, and they do kot know how to use or train it properly. So to them he is severely handicapped to the point that many (less enlightened) would see him as handicapped and inferior.
@Seraphus : That sucks, and unfortunately there is way to much conform or be labeled deficient in society. That and people letting themselves get stuck in mentalities and methodologies that are long sine shown to be deficient. Plus teachers looking to power trip and assert dominance/superiority.
One thing I found amusing when I took an intro linguistics class years ago was that the average Intelligence, err IQ, of someone with certain impediments (stuttering being a good example, including being tormented and belittled for the condition) is actually higher then those who do not suffer from that condition.
There is no excuse for making someone feel Infervor, or publicly shaming someone, because they do not think the same way you do.
Last page of chapter 10, that's the grandpa. I've seen some of the novel's illustrations. Obviously she joins his harem of lolis. This series is quite shameless as you can see.
@eva4hidden in Japan this is incredibly relatable as most people will tell you that they had quite a few asshole teachers throughout their time in school. In the US, everyone has had at least one but Japan has one every grade.