Aoko Aozaki (蒼崎青子, Aozaki Aoko), also known as Miss Blue (ミス・ブルー, Misu Burū) and Teacher (先生, Sensei), is a magician and a member of the Aozaki family. When she was young, Aoko's grandfather, the third generation head chose to raise Touko as his successor while Aoko lived with her parents. She isn't afraid at all of her grandfather, who is labelled a monster, and only thinks of the great mage who called up Magic as "a terrible old man who's lived for a long time through questionable means". However he suddenly changed the position of successor to Aoko. She has a very bad relationship with her sister, Touko Aozaki, who often steals money from the Mage's Association by using Aoko's name.