As Neon Genesis Evangelion is meant as a deconstruction of anime tropes, so is Asuka and Shinji's relationship a darker take on tsundere romance stories.
Asuka and Shinji meet in Episode 8, "Asuka Strikes". Although Asuka finds Shinji to be boring and overly passive, she quickly comes to respect his piloting ability and the two become friendly rivals. Asuka moves in with Shinji and Misato in Episode 9, as the adults note their potential for piloting together. Their relationship grows as the show progresses, albeit subtly, as Asuka remains jealous of his abilities and disgusted by his weaknesses, while Shinji is attracted to her but also confused by her mixed messages. In Episode 15, they kiss, but their relationship only becomes distant from then out. The tensions between the two grow and they are unable to continue fighting together effectively.
In Episode 22, it is confirmed that Asuka has been wanting Shinji's affections, but is too afraid to communicate herself directly to him. Asuka is terrified of being rejected, and simultaneously conflicted by having feelings for Shinji despite his flaws and her jealously towards him. Likewise, Shinji is unsure of how to reach out to her, and fails to understand her hints. Towards the end of the series, Shinji increasingly tries to connect with her, potentially as someone to "save" him, but he finds her over-emotional and confrontational nature confusing.
By the End of Evangelion, Shinji throws himself at Asuka, looking for support. Though Asuka is left comatose after a suicide attempt, Shinji is repulsed by Rei and Misato, and distraught by Kaworu's death. After being given humanity's fate by Rei, his relationship with Asuka proves his motivation. In a surreal and unclear scene, Asuka callously and violently rejects Shinji. Whether real or a product of his own self-loathing, this acts as the final straw in Shinji's decision to trigger the Third Impact and wipe out humanity. Shinji ultimately has a change of heart, but not before the world is all but destroyed.
In the final scene of the show, Asuka and Shinji are alone in the post-apocalyptic wasteland. For unknown reasons, Shinji strangles her, but stops when she strokes his cheek. Their relationship is left on an inconclusive note. While they are together, and with implications that Asuka has come to accept her feelings for Shinji, they are also the only apparent survivors, with even further trauma from the horrors of their experiences. It is left open whether they can come to terms with each other, and whether they or not they will be happy.
- Asuka and Shinji pilot Unit 02 together, defeating the Angel and breaking their sync records.
Both of You, Dance Like You Want to Win
- Hikari angrily blames Shinji when his synchronization with Rei causes Asuka to cry. She orders him to comfort Asuka, which he does.
- Asuka declares her room door "the impenetrable wall of Jericho", a hint that she hopes Shinji will come and support her.
- When half-asleep, Asuka falls into Shinji's bed. Shinji tries to kiss her, which she finds out about the next day.
- The two of them defeat the Angel in perfect synchronization.
- Asuka flirts with Shinji by helping him with his homework, drawing attention to her breasts, and showing off her diving skills.
- Shinji dives into a volcano to save Asuka. Asuka smiles at this.
The Day Tokyo-3 Stood Still
- Asuka tries to comfort Shinji after his call with Gendo ends poorly.
- Asuka returns Shinji's favor in the previous episode by putting herself in danger to protect him.
Those Women Longed for the Touch of Other's Lips, and Thus Invited Their Kisses
- Asuka compliments Shinji on his cello skills, clapping and telling him she is impressed.
- Shinji and Asuka kiss, though Asuka pretends it is only out of boredom. We learn in Episode 22 she was trying to reach out to Shinji for support.
Splitting of the Breast
- Asuka encourages Shinji to take the lead against the Angel, which Shinji does.
- Asuka visits Shinji in the hospital, though she tries to hide herself. Shinji laughs for the first and only time because of this.
- Toji calls Asuka and Shinji "quarrelling newly-weds". The pair has double-blush and makes the denial in perfect sync.
- Hikari notes that Asuka and Shinji always walk home together, and apologizes when she asks Asuka to walk with her instead. This suggests again that Hikari sees Asuka and Shinji as a couple.
- Not unlike Misato, Asuka is reluctant to tell Shinji that Toji was chosen as the pilot.
- Kaji has been encouraging Asuka to reach out to Shinji since before the two properly met.
- Shinji tries to talk with Asuka and find out more about her family.
- The Angel forces Asuka to confront that she has feelings for Shinji, despite his apparent rejection of her.
- Most of the adults are unconcerned by Asuka's pain, and Shinji is the most transparently worried about Asuka, begging Gendo to let him intervene. In the next episode, unaware of this exchange, Asuka laments why she wasn't worth Shinji's help.
- After the attack, Shinji tells Asuka he's glad she's ok, in an apparent attempt to comfort her.
The Beginning and the End, or 'Knockin' on Heaven's Door'
- Shinji monologues that he wishes he knew where Asuka was, and that he wants to talk to her again.
- When Kaworu notes that he was able to take over Unit 02 because Asuka de-synchronized with it, Shinji says "I'm sorry, Asuka".
Take Care of Yourself
- In a reality that evidently reflects what Shinji wishes his life could be, Asuka is his closest friend and apparent love interest.
Love is Destructive
- Shinji makes clear that he is afraid of Misato and Rei, and any desire he may have had for them is gone. He only wants Asuka.
- The pairing's most infamous scene: Shinji begs a comatose Asuka to wake up and help him. When he accidentally exposes her breasts, he masturbates to them.
- While fighting the MP Evas, Asuka complains that Shinji is nowhere to be found, implying she wishes she had his help.
"I Need You"
- When asked by Rei what Shinji wishes for, an image of a woman's clutched breasts is shown. Given the hair style, many believe this to be Asuka.
- In one of the scenes, Asuka and Shinji are naked on top of one another.
- Shinji tells Asuka he wants to help and stay with her.
- Asuka strokes Shinji's face when he strangles her, causing him to break down in tears on her chest. According to extra-canonical info, Shinji had hoped to see Asuka again and had strangled her to confirm he was back in reality.
The dysfunctional and largely destructive nature of Asuka and Shinji's relationship has created a great deal of controversy. Fans of the pairing argue that the two have immense potential as a couple, if they can grow past some of their issues and accept their feelings, as their relationship plays a huge part in exploring the themes of the show as they work as foils of one another. Those who prefer other pairings, especially those who felt uncomfortable with the aggression in Asuka and Shinji's dynamic, typically try to argue that the pairing is abusive. Some additionally try to claim that Shinji's attraction to Asuka was purely sexual.
Possibly in response, further instalments and spin-offs in the franchise have put additional emphasis on Shinji's relationship with Rei and Kaworu. Some material also features more unconventional relationships involving Shinji with Misato, Hikari or Mana. While Shinji and Asuka are still given the most romantic scenes and options, the rival pairings are put on a more equal footing. As a result, the franchise has garnered a reputation as a harem that was not quite accurate for the original show. AsuShin and ReiShin used to be both very popular in the late 90s and early 2000s, with ReiShin featured very prominently after Evangelion 2.0. However, it declined in popularity after Evangelion 3.0, which in turn featured KawoShin, which has also steadily declined in popularity over time. AsuShin, however, remained popular throughout the years, as can be seen in the very large amount of fanwork dedicated to it and the amount of attention it gathers. It is also not uncommon for some shippers to see it as canon or the closest to canon even if it is not their favorite pairing. The fandom still has an active shipping war, with the main focus being on who Shinji should or will end up with in the Rebuild movies.
AsuShin is a possible pairing in all Evangelion video-games that feature such a possibility, though this is often (but not always) also possible for many other pairings, such as Girlfriend of Steel 2 and Shinji Ikari Raising Project, though it is the only pairing featured in games with non-branching story-lines like the Nintendo DS Petit Eva game. In the official manga adaptation, Asuka's personality is changed and there is a lot more attention given to Rei and Reishin. However, the manga ending again features Asuka and Shinji, although they meet in a new world and have no recollection of the events from before, though they seem to have a faint memory of one another. It is also featured in official spin-off manga such as the manga version of SIRP, Evangelion ANIMA, Petit Eva, again with Reishin and Kawoshin usually also present. Angelic Days features an Asushin ending, the only instance of a spin-off ending in which Shinji officially ends up in a relationship with someone. In general, Asushin is the pairing with the most numerous licenced material overall.
- Common AsuShin doujinshi authors include Kuro Tengu, Monkey's Taste, Pengel, ReDrop and Mantou. Those include many non-H and story-focused doujins, largely absent from other ships.
- RE-TAKE series
- EVA-303 by Grunmancant
- Epilogue of Evangelion series
- Theory and Analysis:Shinji and Asuka's Relationship - An article from the EvaGeeks wiki, a major Evangelion fandom center.
- Understanding Evangelion - Anime News Network article which considers their relationship as the most interesting in the show.
- Asuka and Shinji shipping manifesto
- Shinji and Asuka - A forum discussion of Shinji and Asuka's relationship during canon at EvaGeeks
- “Do you love me” theory - Asuka & Shinji Had Sex - Popular theory claiming that Asuka and Shinji had sex in Episode 15.