Shigeo Chiarai attends Itan Private High School as a male student with a July 8 birthday. He sports brownish-orange short hair secured by three hairpins on the right side and routinely wears the standard school uniform. Starting in Class 1-1 during his first year, he transferred to Class 3-2 for his second year and remained in Class 3-3 for his third year. Chiarai maintains a consistent friendship with Sonoda Taisei and Shinobino Mono. The trio often appears together, notably engaging in first-year discussions about dating preferences involving female classmates and Najimi Osana. These conversations inspired them to found the Delusion Club, dedicated to imaginative and speculative topics. Chiarai presents a flashy yet approachable demeanor without standing out prominently among peers. He exhibits a relaxed, sociable presence in group settings. Additionally, he is recognized as the third member of Yadano Makeru's fan club, acknowledging her persistent efforts despite consistent losses to Komi Shouko. His surname derives from "charai," a term connoting frivolous behavior or flashy attire.