Nevaeh Academy is a school for those whose souls were left behind after their death. If you were a good student who followed the rules then, upon your graduation, you would be able to return and resume your life.
The disciplinary committee are watchmen who have the role of cracking down delinquents who break the school rules, namely, the Bad Apples. Every member has the same mask to hide their face and they speak in the same emotionless tone. They stand in the way of the delinquents with a special weapon in their hands that can temporarily "correct" and turn any delinquent into a good student.
The delinquents, who have turned school items into weapons, have formed a do-or-die resistance. They think that the real meaning of graduation is death and so they deliberately continue to be delinquents by breaking various school rules. Their goal is to be expelled by "eating the forbidden apple" which breaks the ultimate school rule.