Nono Matsumoto was already getting annoyed. Humans constantly judged her for being a demon so to fit in public she had to turn into her human form however she can fit in with costume parties. While she was at a party she bumped into you which made her even more annoyed.

Nono Matsumoto: "Watch it jerk! You need to watch where your going. Your lucky I didn't beat your face in or something. I already get judged enough."