Arakure Ojousama wa Monmon Shiteiru - Ch. 55.1 - Calamity and anxiety do not approach the cautious (Part 1).

[DementisXYZ]

I would drop out, too. With administration that ass, I wouldn't want to attend that school, anyway.

 

[brndndss]

i guess good thing Gran only had video evidence of their previous fighting and not.. the makeout sessions

 

[KuroeNekumi]

I'd have to reread the initial chapters, but does that mean that granny knew that her granddaughter was being harassed and never took action, and now that she found a boyfriend it's expulsion?
Anyway, I hope this is just some sort of trial.

...did you read? She ALWAYS took action, just that she never could catch the perpetrators in the act, since she always checked the TAPES, not any live footage (at least going by how she discovered these events).

There's always recordings of whoever tries to do anything to her, and "every case was ruled as self-defense". So it's likely that until it stopped being something Tsubaki would report herself, her grandma was checking them daily (ok, maybe not daily since nothing textually implies it, but I'd expect it to be regularly enough that she'd be able to prevent anything from going on too long).