Aoi serves as a main character, distinguished by light blue hair, glasses, and blue eyes. She typically wears a white top beneath a blue jacket, paired with shorts and blue sneakers.

Frequent relocations due to her father's job defined her early life, fostering loneliness and a deep reluctance to form attachments. This isolation ended when she befriended Subaru in elementary school; their bond provided crucial emotional stability during a difficult time. However, they eventually drifted apart, leaving Aoi with unresolved feelings.

Her personality manifests as tsundere, often masking genuine emotions or desires behind defensive denials or flashes of frustration. This behavior stems from a fear of vulnerability rooted in past separations. Initial interactions with Subaru upon their reunion are consequently tense and guarded, highlighting her struggle to communicate openly.

As a magical girl tasked with collecting engine fragments, Aoi gradually rebuilds trust. A pivotal joint mission leads to reconciliation with Subaru: using a childhood song to synchronize their efforts symbolically mends their fractured relationship. This breakthrough compels Aoi to confront her long-standing avoidance of emotional connection.

A dedicated episode fully explores her backstory and character development. Through magical girl missions and team interactions, she overcomes her fear of impermanence in relationships. By the series' conclusion, she demonstrates significant growth beyond her tsundere tendencies, embracing increased emotional honesty and actively leaning on her friends.