|Affiliations|| Ganta Igarashi|
|Manga debut||Chapter 1|
|Anime debut||Episode 1|
Mimi was Ganta and Yamakatsu's school friend. She was killed during the Nagano school massacre by the Red Man. Ganta had a slight crush on Mimi. Mimi's father also appeared for a short time, though he was only shown in the anime.
Mimi cared deeply for her friends and valued their time together no matter what they did. She was shown to be calmer than the boys and was very polite.
Mimi had long, smooth, black hair and grey eyes. Her bangs hung just above her eyebrows. She was seen wearing a female school uniform.