Ito's acting is very convincing. He plays the role of a nice and "cool" teacher with utmost detail. I've seen several Japanese films regarding schools and it is really one of the better performances. I can't say either what performance is perfect, but I've seen a lot in which I thought "oh come on, he 's definitely not a teacher…".

As for the rest of the film, it's a matter of taste and understanding to some extent. The thing with the Norse mythology, for example. It meant nothing.
It was introduced early so that people could relate to Hasumi's sudden idea of "acting insane" at the end. In general, it's a very Japanese movie. There are not too many cheap jump scares and you calling for it frightens me, a bit.
Too many horror films are ruined by jump scares and cheap scares, besides, horror is not just one kind of horror and this sort of horror is more the gory sense of horror, not a psychological one like, say, Carpenter's Halloween.
Perhaps you had the wrong expectations? Perhaps you wanted to see just another mainstream Hollywood horror flick?

Aku no Kyōten is far from perfect, but it's really not that bad. A solid 7.

The film is a true original.

The reviewer's accusations of hammy acting are completely off base here. The performances are uniformly exceptional.

Surreal, disturbing, suspenseful, nihilistic, erotic, deliciously dark, and unbearably brutal, LESSON OF THE EVIL is a masterpiece.

Claiming you love to watch teenagers being killed doesn't make you cool or hip, Jessica Kiang. Nobody who appreciates this film is loving on its killing of teenagers. This is a cinematic depiction of psychosis featuring an incredible lead performance.

Hideaki Ito displays "minimum acting capabilities"? With this comment, reviewer Jessica Kiang displays minimal perception and zero intelligence. By any measure, Ito performance is amazing.

I hope nobody pays attention to Ms. Kiang's amateurish slam of Miike's latest masterpiece, his best since 13 ASSASSINS, and a tour de force on every level.