Rio's mother, who he most often refers to as his "agent". She gave birth to Rio solely for the purpose of using him to make money. She kept him locked up at home all his life, where the only education he was given was what she taught him herself. At the time, she was sleeping with so many different men that she has no idea who Rio's real father is, but listed the richest man on his birth certificate (despite this man being a different race and obviously not the father).
She is currently dating an American businessman, who she has gone to America to live with, leaving Rio alone at their home in Japan with the promise that she would "be back soon". It is unclear whether she actually intends to return to him or not.
Mimi is cruel and manipulative, using people wherever possible for her own selfish desires. She lies constantly and is disliked by many who know her, particularly those who know the truth about how she treats her son.
