Azusa Nakajō is a student at First High School, recognizable for her petite stature of 150 centimeters and her youthful, almost childlike face, which is framed by short orange hair and accented by green eyes. Her small build often leads to comparisons with a squirrel or a much younger middle school student. Academically, she is among the top students of her year, having entered as the freshman representative, and she excels in both theoretical magic and practical application. Despite this, her personality is notably timid and easily pressured, especially when faced with high expectations or unfamiliar men.

Her deep passion lies in magic engineering. Azusa is a self-described device otaku, fascinated by the intricate technology of Casting Assistant Devices and their programming. This passion drives her primary ambition: to become a professional Magic Artificer. Her technical skill is such that she serves as a technician representative for First High School at the Nine Schools Competition, where she is responsible for CAD maintenance and support. This role brings her into close contact with Tatsuya Shiba, whose extraordinary programming abilities lead her to suspect, and eventually confirm, that he is the legendary and reclusive engineer known as Taurus Silver, creator of the revolutionary Silver Series CADs.

Within the school, Azusa holds significant leadership positions. She initially serves as the Student Council secretary under President Mayumi Saegusa, who affectionately calls her A-chan. Following Mayumi's departure, Azusa is pressured into running for the presidency. She reluctantly agrees only after Tatsuya Shiba warns of potential chaos from past elections and entices her with a prototype Silver Model flying-type CAD, complete with exclusive monitoring equipment. She possesses a rare magical ability called Azusayumi. This is an Informational Manipulative Outer-Systematic Type magic, a form of mental interference that emits hallucinatory sounds and Pushion waves to induce a trance-like state in a wide area, effectively halting panic in a crowd for approximately three seconds. Due to its potential danger, its use is restricted to within the school grounds. She activates this magic using a pendant CAD that transforms into a miniature staff or bow. Throughout the story, Azusa develops from a technically gifted but insecure student into a capable leader who accepts her responsibilities, while still maintaining her core identity as a passionate and dedicated magic engineering enthusiast.