Kōshirō Itome stands at 188 cm, making him the tallest third-year student at Morimori Academy. His light ash-blond or dirty-blond hair falls slightly longer on the right side, often covering part of his right eye. He typically wears a white dress shirt layered under a cream-colored or grey sweater, dark slacks, and red-and-white uwabaki slippers featuring a dark blue stripe. Reserved, quiet, and serious compared to others in the Yarichin Bitch Club, Itome maintains a composed, calm, and sensible demeanor, perceived as relatively normal. Underneath this aloof exterior, he is easily frightened yet demonstrates genuine care for those close to him, expressing fondness for his juniors and showing modesty and kindness. His behavior shifts noticeably around his boyfriend, Keiichi Akemi, revealing deep devotion and submissiveness; he shows affection exclusively in Akemi's presence. Coming from a wealthy family, Itome primarily engages as a top within the club but assumes a bottom role with Akemi. His central relationship with Akemi is marked by deep emotional commitment and romantic gestures, such as enlisting Shikatani's help to select a dress for cross-dressing – an activity Akemi later joined. During a school camping trip, Itome was part of a group that included Shikatani, Yaguchi, and Toono. He has no explicitly stated hobbies or skills. His favorite food is mushrooms, and he reportedly dislikes no particular foods.