"Lesson of the Evil" (Aku no Kyôten) is a psychological horror-thriller film directed by the prolific Japanese filmmaker Takashi Miike. Based on the novel by Yusuke Kishi, the film dives into the dark recesses of human nature through the chilling story of Seiji Hasumi, a high school teacher with a hidden, sinister side.

Seiji Hasumi, portrayed by Hideaki Itô, appears to be the ideal educator—charismatic, engaging, and well-liked by students and colleagues alike. However, beneath his charming exterior lies a sociopathic personality. As the narrative unfolds, it is revealed that Hasumi harbors a penchant for manipulation and murder, driven by his warped moral compass and sociopathic tendencies.

The plot intensifies as Hasumi's true nature begins to surface, and he resorts to increasingly violent methods to maintain his facade and eliminate those who threaten to expose him. The film's tension escalates to a crescendo of brutality, showcasing Miike's signature style of blending intense psychological drama with graphic violence.

"Lesson of the Evil" stands out for its unflinching portrayal of a psychopath in an everyday setting, raising questions about the nature of evil and the facades people wear. Miike masterfully uses suspense, shock, and dark humor to create a disturbing yet compelling film that keeps audiences on edge.

The film's striking visual style, coupled with its haunting score and Hideaki Itô's chilling performance, make "Lesson of the Evil" a memorable and thought-provoking entry in the horror-thriller genre. It is a testament to Miike's ability to explore the darkest aspects of human nature while delivering a gripping and unsettling cinematic experience.