Be advised: this film prioritizes the unfolding events above all else. There’s no satisfying resolution awaiting viewers at the finish, so don’t wait around expecting a neat and orderly ending. Rather, you’ll likely share in the teacher’s sense of aggravation, which I believe was precisely the director's intention. Setting that aside, the fundamental setup involves a school grappling with theft. The central figure—a teacher—obtains substantial but not definitive evidence regarding the culprit. Chaos then erupts as the teacher's existence descends into disarray.

Source on TMDB