Kōji Manabe is a second-year high school student and a member of the folklore research club. He serves as the club's coordinator, taking on the role of organizing and looking after the other members. His personality is serious and earnest, but he also has a clumsy side that sometimes shows through his otherwise composed demeanor. He is described as having a plain or unremarkable appearance that does not immediately suggest a leading character, but he is positioned as the protagonist due to his methodical and scientific approach to problem-solving. Manabe is consistently calm and levelheaded, acting as the group's intellectual center. Under pressure, he tends to rely on logical reasoning and quick thinking to devise plans, often analyzing their surroundings for usable resources. He is notably a fast runner, a practical skill that proves valuable when the group is pursued by the blue monster known as Ao Oni. His primary motivation is to uncover the truth behind the local legend of the Ao Oni, which was turned into a freeware game by a developer who dies under mysterious circumstances. As the mystery deepens and the monster begins actively hunting the students, Manabe's focus shifts toward survival and protecting his fellow club members. He maintains a close friendship with Shoichiro Murakami, another second-year club member who serves as the group's lighthearted mood maker. Manabe also interacts closely with the club president, Junko Takashiro, and the other junior members, functioning as a steady, dependable presence that tries to keep the group cohesive even as fear and danger escalate. Throughout the story, he is forced to confront increasingly dire situations, and his ability to remain composed and think on his feet becomes essential to navigating the horrors of the abandoned school building and the approaching creature.