Kozo is a man of average height and build with chin-length black hair that spikes near the ends. His hands are covered in visible blisters and he wears a Hyottoko mask over his face.
Kozo is usually seen wearing a long, pale robe with a black haori.
Kozo appears as a gentle, soft-spoken individual. He is capable of understanding the hot-blooded Hotaru Haganezuka and cares for others very much as seen when he continues to protect Hotaru against an attack from Upper Moon Five, Gyokko, despite being critically injured.