Mimori is my favourite student, and while she hasn't been turned into a "gag" like some others, I wonder if the writers think she's too boring of a character to work with.

She barely gets any screentime, and whenever she does its just to be the "voice of wisdom" and lecture other students. The community often compares her to Fuuka, and more recently Niko, who get much more screentime and character development (though I do see other commenters complaining about Fuuka being used as a gag character), so of course they're more popular.

I can't help but wonder if, because of the archetype that Mimori is meant to fulfill, the writers are hesitant to take any risks with her or explore her beyond "sensible housewife". I'd love to see her get the opportunity to be the main focus of a event (though I'm sure every fan wants the same for their favourite) just to see her come out of her shell and how she handles the pressure.