Rin Igarashi, 17 years old (18 R2) is a high ranking member of the Order of the Black Knights, and formerly a detective of the Military sent to try to find out the real identity of Zero. She was also the double agent against the Black Knights due to her status as a member of the Royal Guards. However, she doubted the Knights, and on several occasions, helped Suzaku Kururugi before ultimately betraying the Knights. Lelouch vi Britania had shown favoritism towards her and trusted her too much, as she betrayed him, but carried out his last wish for her to protect his sister, Nunnally vi Britannia. Her English voice is provided by Brina Palencia.
Rin is a beautiful young woman with gray eyes and dark red hair in a high ponytail. She is thin, and of average height, but an able fighter nonetheless. She is usually shown frowning, but some characters have commented that her rare smile is beautiful. As a member of the Military, she wore the standard gray armor. As a Black Knight, she wore a black tank top, black shirt, black pants, and a dark blue mask to conceal her identity. As Nunnally's guard, she wears the standard orange jacket with black pants and the orange cap. She always keeps at least two guns on her person.
To most people, Rin appears to be cold and depressing. She is a pessimist, always thinking on the negative side of things. She tends to see everything wrong in everything, which is part of the reason of her betrayal. She is also surprisingly polite and sophisticated to people she knows well. She is an an able fighter, and she is in control of her emotions. She is a fierce fighter and can be loyal to something or someone that has earned her complete trust. This does not mean that she is blindly loyal; she is still able to make her own desicions.
As a detective, Rin is intelligent and observing, noticing things that the average person would skip over. She ultimately did achieve her goal of finding out Zero's identity, even if she had partially switched sides when that happened.
Lelouch vi Britannia: The most notable of Rin's relationships is Lelouch vi Britannia, aka Zero. He was the leader of the Black Knights, the organization which she is a part of. Lelouch shows favoritism towards Rin, and thinks of her as a valuable member and tried very hard to get her to stay in the Black Knights. She is also the first person to know of his true identity and goals, though she still doubts him. Throughout the series, Rin has at first had no idea, then been denying her feelings for Lelouch. She tried to get her mind off this by conspiring with Suzaku Kururugi, Lelouch's rival yet friend. She gave him information about the Black Knights, and is marked as the Traitor. She accepts her real feelings for the rebel after his death, and mourns his death in secret.
Nunnally vi Britannia: Rin and Nunnally aren't shown interacting very much. Before Lelouch is killed by Suzaku Kururugi, he requests that she look after Nunnally, though at first she only did this because of him being her leader, even if she betrayed him. Rin and Nunnally develop a close relationship, with Rin becoming Nunnally's guardian, ready to give her life to protect her.
Euphemia li Britanna:
Kallen Kozuki: Rin and Kallen have a complicated relationship because of their conflicting feelings for their leader. Rin's cool demeanor and Kallen's fiery temper often come into conflict. Both resolve with each other after Lelouch's death.
C.C.: In the past, C.C. gave Rin her Geass. She was almost upset upon hearing about her "death".