this manga has many plot holes to me. The very first and significant hole is the timeline of FL to join the class while the teacher is still teaching.
the story shows that she seems like an innocent girl and knows nothing about the whole class excessive bully plot against the teacher.
however, it shows from time to time in the flashback that FL got transfer in the class while the teacher was still active said like she s new too let try our best.
this is a contradiction. if she transferred when the teacher was still active, how FL knew nothing about the incident. Strange?