In Neon Genesis Evangelion
Asuka Langley Soryu is one of Neon Genesis Evangelion's main protagonist's, who of which pilot's Evangelion Unit-02 and chosen as The Second Child by the Marduk Institute. First brought into the series in episode 8 "Asuka Strikes!". She has a extremely high sync-ratio with Eva when brought into the series that both Rei and Shinji cannot parallel.
She is first introduced as brass, headstrong and confident character, not to mention disliked by a vast majority of the lead characters. Often seeming unsympathetic, insulting and a control freak to some of her peers. She is also a very envious of being beat. Shinji is uncomfortable and somewhat awkward around her. This is probably because Shinji can't seem to comprehend Asuka.
Although this side of Asuka is predominant, she only acts this way towards characters she has expectations for and/or gets in her way. Although towards older people like Kaji, Misato and her family, she acts carefree and joyful. This also goes for some of her friends. She is supposedly "The most popular girl in school" for her confidence, and good looks. The boys even sell pictures of her around the school. She brags to Shinji and Rei about Her popularity. She also uses her popularity to get praise from elders like Misato and such.
Asuka is somewhat of a child genius, having earned a university degree as a teenager, as well as being able to speak fluent Japanese, although she gets bad grades because she has difficulty reading and writing in Japanese (Kanji).
Her guardian in the series is designated to Misato Katsurgi which is the same as Shinji's. Because of this they also live together. She dislikes the home at first, because she is not accustomed living in Japan.
She was born and raised in Germany with an unfortunate childhood, that has severely scarred her for life. Her mother, Kyoko Zeppelin Soryu was a scientist in the Germany branch of The Evangelion Project. At Asuka's mere age of four, Kyoko was a participant in the Evangelion Unit-02 project. Similar to that of Yui Ikari with Unit-01 where Yui did not survive. Kyoko however did survive the experiment, but left somewhat crazed. Kyoko's husband leaves her, and she is left crying every night over him as Asuka watches.
As Kyoko is in a poor mental state, she believes a doll of Asuka's actually is Asuka as an infant. The real Asuka is only known as "that girl over there" to Kyoko that has given her a trauma of doll's. Her mother became unstable to the point where she strangled Asuka, so she can "die with me!". One day in the near future where Asuka is still a young child, she is selected to become a pilot of Evangelion. Running home to tell her mother this and that "people are really nice to me now", she opens the door to her house reveling that her mother has hung herself. Asuka stares at her, stating "Mama looked so peaceful".
After this she vowed to "not depend on anyone".
Asuka hated her step-mother as she was Kyoko's Doctor who married her Father. They both learn to live with each other however, she seems cheerful when getting a call from home. When Shinji was intrigued of this, she replies that
"I just put it on".
She later becomes responsibility for Ryoji Kaji, her new Guardian. She has a massive crush on Kaji going as far as to expose herself in front of him, telling him to "look at me!".
Relationship with Shinji
Asuka's relationship with Shinji is one of the factors in the series and somewhat complex. She does not admit to liking Shinji in front of anyone and seems far too into Kaji to care about anyone else. She is extremely prideful at lets that get in the way to the extent that she can't be open about her feeling's. She often insults Shinji and blames him saying that "All you do is apologize, what kind of man are you!" and "I cant believe I lost to a loser like you!". And on various fronts tries to flirt with him in a indirect way. However all this does is confuse Shinji into ignoring her or telling her "Why don't you be nicer to me!", this gives him the impression that she hates him. Asuka also is disappointed when Shinji gives her these responses.
Asuka gets jealous when other girls like Rei talk to Shinji, however she either takes it out by confronting the girl who he is talking to or Shinji, then insulting them. Probably the closest point where Shinji and Asuka together was when they kissed that was Shinji's first and rumored to be Asuka's first kiss as well. Even this was in no way a declaration of a relationship between them. It simply came out of nowhere when Asuka and Shinji are at home, and Asuka asked "Have you kissed a girl before?". Immediately after what was supposedly a long time kissing, Asuka started insulting Shinji saying "I can't believe I kissed you! Your pathetic!" Then stormed off to her room.
They both like each other but cannot be open with each other. The relationship both intensifies and goes to hell in End of Evangelion. Shinji goes to Asuka who is currently in a comatose state in the hospital, and pleads that he needs her help. However she doesn't wake up. He keeps tugging her shoulder trying to get her to wake up but it is no use. Accidentally, he pulls her away from her bed sheets and her hospital gown. Exposing her breast, he then *without term for a better word* masturbates over
her. Showing Shinji is deeply attracted to Asuka and also pretty fucked up about her too. When he sees that her Eva has been brutally destroyed and killed, he screams and also appears to lose his mental stability. During the time he is in The Human Instrumentality Project, he and Asuka both conflict with each other. There are flashbacks to Shinji of insults Asuka has called him and Asuka saying "You cant understand me, how could you possibly think of understanding me!".
Asuka surprisingly tells Shinji that "I know all about your little jerk off fantasies about me, you can do it right here. I'll even watch you. But If I cant have you all to myself, then I don't what any of you" that is proving that Asuka is willing to accept Shinji but in a very controlling manner, although Shinji just responds saying "Why cant you just be nicer to me"?
Still during The Human Instrumentality Project, at place they first kissed, Shinji tells Asuka that "I need you and I want to help you", Asuka turns him down saying "You don't need me, anyone will do, you don't care who it is!". Asuka continues to go on in this manner but Shinji eventually breaks down and chokes her. In the final scene of End of Evangelion, both are back alive in the real world that is post-apocalyptic of the Third Impact. Shinji starts to choke Asuka who is lying down, however she raises her hand against Shinji's cheek (similar to what his mother used to do) then Shinji broke down crying. Asuka's final line is "How Disgusting". Whether Asuka says this is out of betrayal as in "How Disgusting" you would have choked me. Or spite, as in "How Disgusting" you are is ambiguous. Although this interpretation of the final line probably resides whether they would get along or could never get along.
In Rebuild of Evangelion
In the Rebuild of Evangelion continuity, Asuka's surname is Shikinami, making her Asuka Langley Shikinami. She first appears in the second movie and holds the rank of captain in the Euro airforce. Like most of the other characters in Rebuild, her personality is largely the same, but more mentally stable. All in all, she gets along better with other people than her first incarnation, not repressing her feelings for Shinji as much and eventually even making peace with Rei. The biggest physical difference to Asuka in this continuity is that she loses her left eye much earlier in the story.
In the second movie, Asuka is 14, like in the original series. By the time of the third movie, she is 28, but retains her teenage body because of the growth retardation effect of LCL.