Imi (螢火, Light of a Firefly) is a Xiāochú and a Shinkūmyō. He was trained together with Kowasure Kawahiru, and they became good friends. However, Imi's main goal was a search for power, which contradicted to Kowasure's search for peace, thus leading to both being enemies. Imi later became a major enemy to all of the Soul Society.
Imi is often considered bishōnen due to his slightly feminine appearance even though his attitude strongly opposes this notion. He has long, flowing black hair and slightly lighter eyes. His skin is noticeable pale, which may because of the contrast between. He mostly wears a plain white kimono, something which is quite uncommon because it's generally used in funerals. His footwear consists of flat pointed ankle-high boots. His eyes has been described as "cold and detached". He wears his sword at his right hip, indicating he's left-handed. He is sometimes seen wearing a hitaikakushi, which is a small white triangular piece of cloth tied around the head.