Shigeo Chiarai, formally written as 地洗井 茂夫, attends Itan Private High School and celebrates his birthday on July 8. His surname originates from the Japanese term *charai*—meaning "frivolous" or "flashy"—aptly mirroring his penchant for playful antics and theatrical flair. He sports short brown hair adorned with three hairpins on the right side, complementing his standard uniform. Chiarai forms a trio with classmates Sonoda Taisei and Shinobino Mono, regularly embroidering whimsical romantic scenarios involving female peers. Their discussions spiral into elaborate fantasies, such as casting Komi Shouko as a Meiji-era assassin wife defending him in samurai-themed daydreams. These imaginative tales expose his misinterpretation of Komi’s quiet intensity as intimidating loyalty, oblivious to her social anxiety. The group later institutionalizes their pastime by founding the Delusion Club. His social engagement extends to the Makeru-chan fan club, celebrating Yadano Makeru’s self-declared rivalry with Komi. This affiliation underscores his niche within the school’s social ecosystem, observing dynamics from the periphery. Though outwardly carefree and humorous, Chiarai routinely echoes his peers’ assumptions about Komi’s aloofness, unaware of her communication struggles. His speculative narratives mirror widespread class misconceptions, starkly opposing Tadano Hitohito’s nuanced grasp of Komi’s true character. Documented sources outline no further development or background beyond these interactions.