Mimi is too pure for this story
Someone find an escape route for her
She don't deserve to be here
How is Sensei just now questioning his relationship with Rin
She's been sexually harassing you for a year now
How do you not have any idea of her maybe loving you
She spouts it out of her mouth all the time
The least you can do is take her feelings semi-seriously
Even if it means just turning her down or saying wait until she's older or something beyond letting her continue
Just avoiding her advances/letting her do as she pleases just going to hurt her more in the future
Or just go down the regular lolimanga route and just accept her
He needs to pick Order or Chaos soon before all of it just spirals into a horrible mess that can't be contained