Yoichi was a young man with a sickly and malnourished appearance and a weak body. He had white, messy hair, similar to that of Tomura Shigaraki. His hair reached to about his shoulders, and his bangs usually obscured his bright green eyes, which gave him a sinister appearance not consistent with his benevolent personality.
During his lifetime, he dressed in simple clothes, wearing a white shirt and dark pants. He would occasionally be seen wearing a light blue jacket.