Miss Ayumi teaches at Graviton High School, specifically managing the class containing A-ko, B-ko, and C-ko. Her duties center on mediating clashes between A-ko and B-ko while striving to educate C-ko, a role exposing her to significant stress due to constant destruction from student battles.

Her visual design draws inspiration from the protagonist of the 1980s magical girl series *Creamy Mami*. Beyond teaching, she serves within the city's Public Works Defense Force. During *Project A-ko 3: Cinderella Rhapsody*, she participates in a military operation aimed at containing collateral damage from a confrontation between A-ko and B-ko.

Later, in *Project A-ko 4: FINAL*, her personal life becomes entangled with the Daitokuji family's schemes. Hikaru Daitokuji, B-ko's father, orchestrates an arranged marriage between her and Kei. This situation places her at the center of conflict as both A-ko and B-ko, infatuated with Kei, actively attempt to sabotage the wedding. Her involvement extends beyond the school into broader corporate and alien-related conflicts within the series.

Her narrative progresses from an educator navigating classroom chaos to a participant in city defense operations, and finally to a key figure in interpersonal conflicts driven by external manipulation. She maintains a professional demeanor despite recurring challenges.