There is a strange disconnect between everyone in the cafe saying "Ewh, what's with that weird girl?" when the art for the girl is this cute, aesthetically pleasing design common to anime. I suppose you need to be able to suspend your disbelief, but for me it was just a little too far for me to believe it. I feel like being mindful of the character's design should be important for this kind of game - and not just about making a pretty waifu for weebs to drool over.
This is explained in the game. Most people are repelled by her because of her curse, that's the reason she draws scorn from others, not because of her appearance or mannerisms. As far as I know there's nothing else meant to be wrong with her.