Setsuko Gidou

Setsuko Gidou enters the story as a journalist for a women's magazine—striking in appearance, fair-skinned, and effortlessly captivating. Her habit of casually calling protagonist Sohei Saikawa by his first name and their notably close dynamic initially led Moe Nishinosono to suspect a romantic rivalry. The truth, however, proved far less dramatic: Setsuko is Saikawa's biological sister. She arrives at the Magata Institute on an assignment, and stands out as one of the rare few who can coax a visibly relaxed, unguarded side out of the typically aloof Saikawa.