Rae told me their story and why she wanted to go back to the way it was.
As the former knowledge-reliant girl, she was kind of really vulnerable during her childhood days. No one would stick to her side and most kids would find her annoying. And according to her, even her older siblings couldn’t stand her. They always called her ‘Miss Know-it-all’ and instead of trying to understand her, most would just not bother to talk to her.
It was only during her 5th grade that she got to know Yoko-san. At that time, the maid was already in her last year of high school. She’s one of their guests at some kind of ball or party where Rae was really out of place.
It was full of adults and none of the kids were all running around not bothering her.
Yoko-san apparently ran away from someone who was trying to flirt with her and found Rae in some kind of study, busy with her books, accumulating more knowledge.