When I saw the "end" tag, I thought to myself that he will ask Mino-san about her horns and in response she will slowly fade away, thus ending the series.
@Tyco2003 Or Just tell her "My ability is whatever you imagine it to be. Now imagine that I can pull golden ingots and nuclear grenades out of thin air"
@Acolytus @Darklight99
This guy does not understand what she feels, and that provokes him to bully her, even though he is attracted to her.
Oh well, this is manga anyway. Let's not take it seriously.
I had to stop reading halfway through because I finally realized.
She has a facial muscle/nerve dysfunction/paralysis. And yes, I heard couple stories of people getting bullied for not being able to show any emotion on their face even if they laugh.