Rei Ayanami (綾波 レイ[?], “Ayanami Rei”) is a fictional character from the Neon Genesis Evangelion franchise. She is the First Child (First Children in the Japanese version), pilot of the Evangelion Unit-00 and one of the female main characters.
At the beginning of the series, Rei is an enigmatic figure whose unusual behavior confounds her peers. As the series progresses, her personality evolves and she becomes more involved with the people around her, particularly her classmate and fellow Eva pilot Shinji Ikari. She is revealed to be a key factor in the events that conclude the storyline. Her role in this conclusion is not made clear in the TV series, but is one of the principal plot points of The End of Evangelion.
No specific information is given about Rei’s origin or heritage. Ritsuko Akagi states that Rei was born in a certain room deep in the lower levels of NERV headquarters, but this is all that is explicitly revealed in the series about her creation. The Red Cross Book stated that Rei was created from the “salvaged remains” of Yui Ikari after Yui’s absorption into Unit-01 in 2004. The connection between Rei and Yui is implied a few times during the series. Gendo introduces Rei to the NERV staff in 2010 as an “acquaintance’s child” whom he is temporarily taking care of. In episode 21, Naoko Akagi says that Rei physically resembles Yui. The character model used in the 2010 scenes is based on development materials in which her age is only 4.
Kaworu Nagisa cryptically mentions in their only conversation that she is “the same” as him. This statement was expanded in the “director’s cut” of the episode, in which Kaworu goes on to say that he and Rei are human vessels for the souls of Adam and Lilith, respectively. Later in the episode, she generates an external A.T. Field which is as strong as Kaworu’s. In a pseudo-hallucinatory scene in episode 25, “Gendo” tells “Rei” that the day of Third Impact is the day for which she was created. In The End of Evangelion, she plays an important role in Third Impact, although not in the fashion that was intended by Gendo.
Rei is shown spending unknown lengths of time in an LCL-filled tube underneath a structure resembling a giant brain in the Dummy System room, the reasons for which are not revealed. The circular wall of this room is originally depicted as being covered with DNA sequences, but near the end of the series, it is revealed to be an LCL-filled tank in which dozens of soulless clones of Rei are held. The clones are said by Ritsuko to be the cores of the dummy plugs; she also refers to them as “spare parts” and later as “vessels” for Rei. The movie pamphlet and volume 11 of the manga states she can be replaced entirely, with her soul being transferred to a new clone body every time she dies, although her memory becomes muddled with each transfer. Other supporting evidence in the anime include her earlier line that “if I die, I can be replaced.”
These different incarnations are commonly referred to as “Rei I,” “Rei II,” and “Rei III,” after episodes and musical pieces with the same names. In episode 23, the controller that Ritsuko uses to destroy the clones lists numbered clones from “Rei 004” and upwards. Rei I was the very first clone. She was murdered by Naoko Akagi in 2010 (as shown in Episode 21). Rei II is the clone introduced in the first episode and who appears in most episodes of the series. She dies when she sacrifices herself and Unit-00 to destroy Armisael in episode 23.Rei III is the version seen from the second half of episode 23 through to The End of Evangelion.
In the final episode of Neon Genesis Evangelion, the audience is introduced to a pseudo-hallucinatory alternate reality, with a different Rei. This Rei’s personality is completely different, and her behavior is more “normal” (for example, she shows embarrassment and anger when she thinks Shinji looked up her skirt, in stark contrast to her emotionless reaction to the incident with Shinji in Episode 05). The Evangelion spin-off manga Neon Genesis Evangelion: Angelic Days is set in this alternate universe, and its version of Rei is a central character.
In The End of Evangelion, a shining figure of Rei is shown for a few frames looking down at Misato and Ritsukomoments before they die. These spectral images also appear over the corpses of the slain NERV personnel.