C.C. is a mysterious green haired girl who looks like she is 16 or so. She is shot while saving Lelouch in the first episode, but while presumed dead, she was still able to give him the contract of the Geass. Many have called her a witchvbecause it is impossible for her to die. In certain flashbacks, she was seen burning at a stake, presumably done by villagers who thought she was an evil witch. She was orphaned at a young age and once a slave. After running away she was taken in by a nun with the 'code' who gave C.C. her geass. Since the geass gives the user what he/she desires, C.C. was given the power to be loved. When C.C.'s geass was more developed, the nun tricked her into killing her, and thus gaining the code for herself, which she did not want.

Not much is known about her in season 1, other than the fact that she is Lelouch's "accomplice." During the less serious parts of the show, she is the comedy relief, as is shown by her obsession of pizza. C.C. uses Lelouch's credit card to buy pizza from Pizza Hut, and she is even called Pizza-kun by Lelouch and Kallen.

C.C. gives Lelouch the geass and helps him out and even joins the Black Rebellion so that he can survive and fulfill his contract. She never reveals what the contract is, until season 2, where it is revealed that her goal in life is to die. She has been living too long, and this eternity is too much to bear. Thus, she is loyal to anyone whom she gives the geass to, who can fulfill that contract. She sticks with Lelouch until she runs into Charles, who already has the code and can take her life. For an unknown reason, C.C. ends up changing her mind and survives.