Aria Kisaki is a female high school student and a key character who brings a vibrant, energetic presence to the story. She is a second-year student who attends a different school than most of the main cast, but she becomes a regular and beloved presence in their circle.

Aria's background is defined by her family situation. Her father, Yoh Kisaki, is a manga artist who left home after his series was canceled and subsequently divorced his wife, leaving Aria to be raised by her mother. Her mother, who works as a department store clerk, was also a "gyaru" in her youth, and Aria's appearance is strongly reminiscent of her mother at the same age. Living in a single-parent household with a busy mother, Aria developed significant skill in cooking, often preparing meals at home.

Physically, Aria has a striking appearance with blonde hair and is characterized as a classic "gyaru," a style associated with being outgoing and fashion-forward. She has a toned, athletic figure and a large appetite, which she maintains through regular exercise. While her natural skin is fair, she is known to tan herself for cosplay roles that require a darker complexion.

Aria's personality is overwhelmingly bright, sociable, and friendly. She has a natural ability to connect with people and is not one to impose her own views on others, making her well-liked. However, beneath this confident and bold exterior lies a surprisingly sensitive and romantic heart. She is easily frightened, particularly by things like haunted houses and tests of courage, and can become quite shy and flustered, especially regarding her own feelings.

Her primary motivation for becoming a cosplayer is deeply personal. Initially a novice with little to no knowledge of manga, anime, or otaku culture, her goal is not born from a pre-existing fandom but from a desire to be found. She wants to become a famous cosplayer so that her estranged father, who has been missing for years, might see her and know that she still loves his work and has not forgotten him. This drive leads her to cosplay as Melia, a character from her father's old manga, Valkyrie Front, at her first major event.

Aria enters the main story by approaching the group of Masamune Okumura, Lilysa Amano, and Nonoa during a joint cosplay photoshoot. Despite being an outsider and initially clashing with Nonoa, who is skeptical of her lack of otaku knowledge, Aria's sincerity and enthusiasm win them over. She begins to visit the Manga Research Club room to learn about otaku culture and improve her cosplay skills, which were initially rudimentary but improve significantly over time.

Her key relationships evolve significantly throughout the story. Her bond with Nonoa transforms from initial antagonism to a deep and close friendship. She also develops a strong friendship with Lilysa Amano, who helps her learn the ropes of cosplay. Aria gradually develops romantic feelings for Masamune Okumura, who is supportive of her dreams and her quest to find her father. She makes subtle, often shy, attempts to get his attention, though his characteristic obliviousness means these hints frequently go unnoticed.

Aria's most significant development is the resolution of her family story. At a large summer convention, her cosplay photo, which makes her look strikingly like her mother when she was young, circulates online and reaches her father. Realizing who she is, he rushes to the convention, leading to an emotional reunion after ten years of separation. This event not only reconnects Aria with her father but also leads to a gradual reconciliation between her parents. Through this journey, Aria evolves from a complete outsider with a secret agenda into a passionate and skilled cosplayer, a loyal friend, and a young woman who successfully bridges the gap between her family and her new-found passion.