Talk:Akane Shinjo/@comment-3024153-20181125174455/@comment-35573414-20181224085445

Isn't it covered in the episode? She hates the school festival because it involves the students doing things outside of her control, having fun without her. She hates the school festival because everyone else is having a good time, and she simply can't (for a ton of reasons).

By the end of the series, we can also reasonably infer that the school festival hits her close to home — it's a close reminder of the real world that Akane is trying to escape from, and potentially a reminder of real-world bad experiences that she had from school festivals in the past.