Too frightened to face Misato or Rei, Shinji runs away yet again, only to meet and strike a friendship with Kaworu Nagisa, the replacement pilot for EVA-02. Kaworu's openness and friendliness provide much-needed comfort for the disturbed Shinji. However, suspicions abound over Kaworu's incredible synchronization abilities.
Asuka's synch rate is on a downward spiral after her defeat at the hands of the Fourteenth Angel, Zeruel, and her frustration with Rei, Shinji, Misato and Ryouji is on the rise. Angrier and more disturbed than ever, she is forced to relive her dark, traumatic past during the encounter with the Fifteenth Angel, Arael.
Kouzou Fuyutsuki is kidnapped and interrogated by Seele, who are horrified over the results of the last encounter with an Angel. He recounts his past, providing flashbacks into the creation of Nerv. The pasts of Misato Katsuragi, Ritsuko Akagi, Rei Ayanami and Yui Ikari are also revealed. Ryouji Kaji, meanwhile, decides to find out the truth, no matter the cost.
Evangelion Unit-03 arrives from the United States. However, its activation experiment brings out NERV's worst nightmare when it turns out to have been infected by the Thirteenth Angel. The other EVAs are dispatched to battle the Angel-infected abomination... even at the risk of killing its helpless pilot.
Shinji beats Asuka in a synch test, much to her annoyance. Not too long after, the EVAs are dispatched to deal with a mysterious apparition, and EVA-01 is sucked into a shadowlike blackness that materializes out of nothingness from under it. While an emergency operation to rescue the captured EVA is concocted, Shinji goes on a trip into the depths of his own consciousness...
In the first half of the episode, a clip show is presented to the Human Instrumentality Committee of Seele, reviewing the attacks of all Angels up to this point. The second part includes a poem in which Rei contemplates her own existence, and a cross-compatibility test between Rei's and Shinji's EVAs.
A routine test involving the EVA pilots turns into a struggle for survival when a wholly new type of Angel appears and spreads inside NERV HQ. This new, computer-like angel threatens to set off the self-destruct for the entire facility, leaving Dr. Ritsuko Akagi in a race against time to save the GeoFront and destroy the Angel.
The EVA pilots are disappointed to find out that they are not allowed to go on their class trip to Okinawa, because they have to stay at Tokyo-3 to stay on-call in case of an Angel attack. Meanwhile, a new Angel is discovered in a chrysalis-like developmental stage deep within the magma of the volcano Mount Asama.
Asuka joins Shinji’s class at school, and moves in with Misato and him in their apartment. As Asuka adjusts to Japan (or rather, everyone else adapts to her...), a new Angel attacks which is capable of splitting itself into two identical copies. EVA-01 and EVA-02 are defeated, and NERV is publicly humiliated. With the Angel in a week-long regeneration period after an N² Mine attack by the JSSDF, Asuka and Shinji must learn to "synchronize" with each others movements combat, in order to defeat it once and for all.
Misato brings Shinji, along with Touji and Kensuke, to a massive UN naval convoy transporting Evangelion Unit-02 and its fiery German pilot, Asuka Langley Souryuu, to Japan. Escorting Asuka is Misato's old boyfriend, Ryouji Kaji. After some awkward introductions and reunions, the fleet is attacked by a massive aquatic Angel. Asuka powers up Eva-02, and decides that she will defeat the Angel by playing "hopscotch"...
Ritsuko briefs Shinji on the real nature of Second Impact, the Angels, and the Evangelions' mission to defeat them. Misato and Ritsuko attend the public demonstration of a new Angel-fighting robot, Jet Alone, built by a rival defense contractor to NERV. However, the nuclear-powered robot quickly runs out of control, and Shinji must use EVA Unit 01 to load Misato onto Jet Alone so she can she can enter in its automatic shutdown code, before it melts down in a nuclear explosion.
Continuing from the previous episode, the Angel Ramiel is drilling down into the GeoFront to attack NERV HQ directly. After Shinji barely survived a direct confrontation with it, Misato devises a plan to have EVA-00 and EVA-01 defeat the Angel by sniping it from a distance using a positronic rifle which requires the total electric output of Japan to power up.
EVA-00 is finally repaired, and Shinji tries to get to know its enigmatic pilot, Rei Ayanami, better. However, he is confounded because she is extremely insular, has no friends at all, and the entire record of her past has been erased. In the midst of this, a very powerful Angel, the floating monolith Ramiel, attacks Tokyo-3.
Shinji begins attending his new school in Tokyo-3, and has a difficult time dealing with the fame of being an Evangelion pilot. Touji Suzuhara, who's little sister was injured in Shinji's fight against the Angel, is angry at Shinji. A new Angel appears, and Shinji must once again pilot EVA-01 to defeat it.