Hikari Horaki is a student at Tokyo-3 Municipal Middle School and serves as the class representative for Class 2-A, the same class attended by the Evangelion pilots Shinji Ikari, Rei Ayanami, and Asuka Langley Shikinami. In Evangelion: 1.0 You Are (Not) Alone, she is a familiar presence in the school environment, helping to maintain order and protocol within the classroom. Physically, Hikari is recognized by her brown hair, which she typically wears in two pigtails, and her distinctive freckles; her school uniform includes a white shirt, blue dress, and a red bow.

Hikari takes her responsibilities as class representative very seriously and presents herself as a diligent and somewhat strict figure who ensures her classmates follow the rules. On the surface, she can appear bossy and quick-tempered, but this stern exterior hides a more caring and warm-hearted individual. She is an accomplished cook and, out of a sense of duty, takes care of her two younger sisters, Kodama and Nozomi, which reflects her responsible nature outside of school as well.

Within the narrative of the first Rebuild film, Hikari's role is primarily that of a supportive classmate. An important distinction in this version of the story is her relationship with Asuka. Unlike in the original television series where they become close friends, in Evangelion: 1.0 You Are (Not) Alone, their connection is more distant; a notable moment occurs when Hikari offers to share her lunch with Asuka, who refuses the gesture. She also has a dynamic with the boy Toji Suzuhara, with whom she frequently bickers, a behavior that masks her hidden romantic feelings for him. Hikari has no special abilities or piloting skills within this film; her significance lies in being a grounding presence who, along with her classmates, represents the ordinary civilian life that the Evangelion pilots are fighting to protect.