In Chapter 17, the kids have been on a school trip to Kikko National Park, and neither Shuuichi or Takatsuki have been having a good time. Some Jerk Ass little brat has been bullying Shuichi (though not in view of the teacher), making fun of her and calling her "gayboy," and just making the trip unpleasant overall. However, in the hotel cafeteria on the second day, Saori decides she's had enough and calls him out on it. He tries to make it look like she's the one who's a bully, which causes her to snap in an awesome way:
"If someone teases you for having red hair, the first thing you should do is break your slate over his head. But don't forget, you will get scolded by teacher, big time."