Teiko Shinazugawa

Teiko is a girl of average height with fair skin. Her black hair is tied back in a bow, and she has large, almond-shaped purple eyes. Her looks closely resemble those of her brother Sanemi. She wears a mint green kimono patterned with white wavy stripes and fastened with a lime green obi.

Like her siblings, Teiko is loving and tenderhearted. She is devoted to her mother and worries for her safety, covering her own eyes during their father's violent outbursts because she cannot bear the sight and staying awake to wait whenever her mother comes home late. When she wakes one night to find Sanemi and her mother gone, she turns to Genya for comfort, fondly looking to her older brother.

Teiko is born to Kyogo and Shizu Shinazugawa, one of seven children, with Sanemi and Genya the eldest. Their abusive father torments the family until he is eventually stabbed to death by someone seeking revenge. One night their mother fails to return home, and Sanemi sets out to search for her while Genya stays behind to watch the younger children. As dawn nears, their worry grows, since she has never been so late before. When a knock comes at the door, Teiko and several siblings rush to greet her. Despite Genya's warning, the door bursts open and their mother, now a demon, charges inside and kills Teiko at once.

The memory of her death returns to Genya during the Swordsmith Village arc as he faces Hantengu and his life flashes before him. Much later, in the Sunrise Countdown arc, Sanemi sees Teiko and his other fallen siblings in the afterlife as he lies dying from his wounds in the final battle against Muzan Kibutsuji.