Single mother Saori lives with her 11-year-old son Minato. She notices that he’s been acting oddly lately, seemingly because of physical and verbal intimidation by his class teacher, Mr Hori. But the school brushes off the accusation with an unconvincing apology. The situation is complicated even more by the perspective of the accused teacher. Who is actually the “monster” in the film’s title? This outstandingly well-written film is not only about fear, loneliness and friendship presented from different perspectives, but also about the blind spots that sometimes lead to unambiguous moral judgements even when the facts are not so clearcut.