Aira Shiratori is a high school student and classmate of Momo Ayase and Ken Okarun Takakura, initially introduced as one of the most popular girls at Kamikoshi High School. Her background includes a unique and tragic connection to the supernatural. As a young child, Aira possessed the ability to see spirits and, after losing her mother, she encountered a wandering ghost and mistook it for her deceased parent. This spirit, who would later be known as the Acrobatic Silky, became obsessively attached to Aira, following and protecting her from the shadows for years, eventually transforming into a powerful yokai.

On the surface, Aira presents herself as a sweet, kind, and innocent natural beauty, a persona carefully crafted to maintain her status at the top of the school's social hierarchy. Beneath this facade, her true personality is initially revealed to be vain, self-centered, arrogant, and cruelly manipulative. She demonstrates a mean streak by mocking Okarun behind his back and spreading vicious, false rumors about Momo to protect her own reputation. This behavior leads Momo to see through her act, creating an immediate conflict between them. However, Aira is not a static character; her core is fundamentally altered by her experiences. After a near-death encounter with the Acrobatic Silky, she begins a significant redemption arc. While she retains a somewhat bossy and overly dramatic demeanor, she evolves into a more genuine, heroic, and loyal individual, even publicly confessing to her past lies and accepting the social consequences.

Aira’s primary motivation undergoes a dramatic shift. Initially driven by a desire for social dominance and self-preservation, her actions change after she finds one of Okarun’s golden balls. This object reawakens her latent spiritual powers, leading her to believe she is a holy warrior chosen to defeat Momo, whom she mistakenly identifies as a demon. This misguided crusade brings her into direct conflict with the main duo and the Acrobatic Silky. When the yokai attacks and mortally wounds her, the Silky sacrifices its own aura to revive Aira. Experiencing the Silky’s tragic memories of losing her own daughter, Aira gains a profound new purpose: to honor that sacrifice and fight to protect others, vowing never to forget the spirit who saved her. She subsequently joins Momo and Okarun, becoming a dedicated ally in their battles against both yokai and alien threats.

In the story, Aira serves as a key member of the main protagonist group, often acting as a foil to Momo. Her role evolves from an antagonist to a rival and finally to a trusted, if sometimes comically self-important, comrade. She frequently positions herself as the leader of their group, a claim the others mostly ignore. Her key relationships are central to her development. Her dynamic with Momo transforms from bitter enmity to a strong, bickering friendship built on mutual respect. She develops a sincere, albeit unrequited, romantic crush on Okarun, whom she sees as a hero, leading to moments of jealousy and comedic rivalry with Momo for his attention. Her relationship with the Acrobatic Silky is the most poignant; she carries the spirit's powers and memories, fighting as a way to give meaning to the Silky's tragic existence.

Aira’s character development is one of the most pronounced in the series, marked by a clear arc from a hated figure to a fan-favorite hero. Her journey is one of taking accountability, learning humility, and discovering genuine courage and selflessness. The near-death experience and the emotional weight of the Acrobatic Silky’s sacrifice serve as the catalyst that cracks her narcissistic shell, allowing her to grow into a reliable and brave fighter who consistently puts herself in danger for her friends. She matures from someone who weaponized her popularity to someone who uses her newfound strength to protect her community.

Aira’s notable abilities are a direct result of the Acrobatic Silky’s sacrifice. She inherited the yokai’s supernatural powers, allowing her to transform into a form resembling the Silky, complete with a spectral mask and incredibly long, flowing hair. In this form, her physical capabilities are greatly enhanced, granting her superhuman strength, speed, and agility that she uses to perform graceful, acrobatic combat maneuvers and powerful kicks. Her primary weapon is her prehensile hair, which she can extend and control to whip enemies, grab objects or surfaces for three-dimensional maneuvering, bind opponents, and obscure their vision. As she gains experience, she develops more sophisticated techniques, such as the Pirouette Noble Drill, where she wraps herself in her hair and spins her body to drill through enemy armor with devastating force. Unlike Okarun, who borrows power from Turbo Granny, Aira’s abilities are implied to be her own awakened spiritual power, allowing for more flexible and frequent use of her transformation.