Aku no Kyten ? , literally Lesson of Evil , known in English as Lesson of the Evil, is a 2012 Japanese slasher film directed by Takashi Miike, starring Hideaki It. It is an adaptation of Yusuke Kishis 2010 novel of the same name. The film contains many references to German culture, such as to Goethes The Sorrows of Young Werther and in the film a vinyl record with the German song about Mack the Knife written by Bertolt Brecht is played.
Back in Japan, Hasumi chooses to deal with problems like bullying and student sexual harassment, starting by dealing with the school cheating issue. Upon collecting all of the students cell phones prior to their exams, Hasumi secretly uses a cell phone jammer to completely prevent any cheating during the test. The group of students that had cheated on previous exams became suspicious after none of the groups cell phones have service during the test and immediately suspect the adviser of the Radio Club, Tsurii a loner Physics teacher. They are then confronted by Tsurii himself who clarifies that he was not responsible for the jamming. A man who regularly meets with the school to complain about students bullying his daughter, Rina, is murdered. Someone has replaced the bottles of water he kept around his house to scare off cats with kerosene, as the man is a chainsmoker the bottles soon catch fire and explode. Tsurii soon meets with the intelligent ringleader of the cheating group, Keisuke, revealing his suspicions of Hasumi. Tsurii explains he has dug into Hasumis past and found strange details, such as at another school where Hasumi started his teaching career that later had four student suicides. During this time, however, Hasumi had bugged the room and learned of Tsuriis suspicion, and confronts him on a train, murdering him and making his death appear as a hanging suicide. Hasumi then confronts Keisuke after the announcement of Tsuriis suicide causes him to panic. Hasumi knocks Keisuke out and ties him up until the end of school, after which Hasumi tortures him into admitting that he and his friends were indeed cheating. Hasumi checks that Keisuke didnt tell others of Tsuriis suspicions, before killing him and hiding his body.During the same time period, Hasumi is brought to the attention of a blackmail case from one of his students. A store owner, Meka, caught a female student, Miya, shoplifting but swears not to charge her for it. However, PE teacher Shibahar
Source: Wikipedia