Genya is a young, rough-looking demon slayer with a "lone wolf" personality, characterized by his impatience, ill-temper, and foul mouth, who also has a distinctive mohawk-styled buzz cut and slanted, violet eyes. He has scars all over his body. After consuming demon flesh, Genya gains demonic characteristics like fangs, dark sclera, and unique yellow tips in his hair. He has an older brother, Sanemi Shinazugawa. Genya lost his family at a young age. He has a soft spot he only shows to Muichiro.