The only son of Gendo and Yui Ikari. He is a quiet, model-student type who is excessively introverted, humble, and socially awkward. He possesses cowardly and escapist tendencies, and because he is more aware of these traits than anyone, he tends to evaluate every situation self-deprecatingly and think negatively. He harbors complex emotions and intense pity for Asuka. He feels a sense of preciousness toward Rei and deep resentment toward Gendo. He relies on Misato as his guardian.

Possessing a truly blunt personality, she remains expressionless 24 hours a day and speaks only when necessary. Her voice is robotic, maintaining a constant tone without inflection. She is a clone. Initially obedient to Gendo, she increasingly struggles with her identity and eventually comes to reject him.

On the surface, she appears cheerful and energetic, but this is merely a persona—a mask worn to function socially while covering an inner self so wounded it can no longer move. Ritsuko speculates that her current bright personality is a compensation for her childhood experience of elective mutism; perhaps because of this, she tends to force a cheerful demeanor whenever the atmosphere turns dark. She was in a relationship with Kaji and suffers greatly after his death. Nevertheless, she strives to protect Shinji and Asuka until the very end.