The least believable part is that the whole class seems to be in on the plan? Like the bullies loudly talked about it in front of everyone and then the confession happened in the classroom. This whole game would fall apart if there's a single person in the room decides to tell one of the friends.
90% chance the bully later becomes her friend after she loses her social hierarchy
10% chance she gets what she deserves later on and our mc doesn't help her instead puts her in her place, and im being generous with the 10% here
Also, one thing i like to point of is that it seems that all of the fucking classmates are either non existence or just straight up pussies cause damn bro the bully be havin cartoon network villain syndrome speech 101 with her dumbass telling the "pranks" outloud in the classroom
awwww. this is too wholesome and sad at the same time but I am hoping for the best of both of the mc and fmc. Something lovey dovey serious stuff to be the ending.