Kōichi Shidō is the teacher of Class 3-A at Fujimi High School. He is despised by Rei Miyamoto, who harbors fear and disgust for him due to his past actions. Similarly, Saeko Busujima expresses disdain for him, referring to him with a scowl. Shidō’s actions and demeanor establish him as a cruel and manipulative character, embodying the darker side of human behavior during the apocalypse.

Shidō’s true nature is revealed early in the series. During the initial chaos of the outbreak, he leaves behind a student who has sprained his ankle, showing no remorse as he even kicks the injured student back toward a group of zombies. This act exemplifies his belief in survival of the fit and his complete lack of empathy. Following this, Shidō makes a speech to his remaining students, claiming that weaklings do not deserve to exist and promising “peace” to those who follow him, using fear and charisma to establish a cult-like control over his group.

His manipulative leadership and disregard for human life create significant tension and highlight his role as an antagonist in the story.

Kōichi Shidō is depicted as a slim man with a thin frame, often dressed in a black pinstripe suit paired with a white dress shirt and a yellow tie. He completes his attire with black-framed glasses and brown dress shoes, presenting an outward appearance of professionalism and composure.

Despite his outwardly polished look, Shidō’s expressions frequently betray his true nature. He can switch from a calm, seemingly peaceful demeanor to one filled with hate and scorn, reflecting his manipulative and sinister personality. His frail and unassuming appearance often works to his advantage, allowing him to deceive and manipulate others into trusting him before revealing his true malicious intentions. This contrast between his appearance and his actions underscores his role as a deceitful and dangerous antagonist in the series.

Shidō is manipulative, egotistical, and sadistic, using the zombie outbreak as an opportunity to exploit and control others. He thrives on power and control, using fear and persuasion to manipulate his students into loyalty. Despite his outward appearance as a composed and intelligent leader, Shidō is deeply malicious and untrustworthy.

He shows little regard for human life, willing to sacrifice others for his own safety and goals. His twisted sense of morality and lack of empathy make him a true antagonist within the series. Shidō’s behavior reflects a complete disregard for ethics, further exemplified by his treatment of Rei and the cult-like environment he fosters among his students.

Shidō serves as a significant source of tension within Highschool of the Dead. His manipulative actions create conflict both within his group of followers and between himself and the protagonists. After being rescued by the main group, his morally corrupt nature quickly becomes apparent, leading to a confrontation with Rei, who harbors a personal vendetta against him.

Eventually, Shidō is expelled from the Takagi Estate due to his actions, and his cult of students begins to unravel. His ultimate fate remains ambiguous, but his presence leaves a lasting impact on the characters, particularly Rei and Takashi Komuro, who come to understand the dangers of individuals exploiting the apocalypse for personal gain.