Yayoi Aoyagi, approximately twelve years older than her sister Kanna, founded the eroge production company Blue March out of financial necessity after their father's death. This decision aimed to secure Kanna's future and support her college education, positioning Yayoi as a parental substitute while their mother worked additional hours. As company director, Yayoi exhibits pragmatic leadership characterized by assertiveness, blunt communication, and low tolerance for complaints. She recruited Kanna as a voice actress immediately following her 16th birthday, circumventing legal concerns while acknowledging the role's inappropriateness for a minor. Her recruitment similarly leverages the enthusiasm of other young employees like Hadzuki and Kotori.

Yayoi employs rigorous, unconventional voice acting training techniques, prioritizing results over comfort. She shares embarrassing anecdotes about Kanna with coworkers and suggests potentially questionable methods to enhance performance realism, maintaining composure during controversial proposals. Historical parallels reveal she initially experienced similar embarrassment about eroge work before becoming desensitized, though referencing her sole voice acting performance triggers strong reactions. Her management includes manipulating situations for desired outcomes, such as provoking Kanna's involuntary "ero-mode" trances to capture authentic recordings and slapping her to break the trance when necessary.

Financially motivated due to the company's limited profitability and inability to afford experienced voice actors, Yayoi works extensively. This drives her reliance on Kanna and acquaintances, accepting long hours and minimal leisure time. Despite her stern exterior and occasional ruthless decisions, underlying concern for Kanna surfaces through birthday gifts and sacrifices for her future. Their relationship embodies a sibling dynamic where Yayoi's assertiveness and comfort with explicit topics contrast Kanna's shyness, though Yayoi remains protective in her own way. She assures Kanna about anonymity at events like Comika, though these assurances sometimes prove misplaced when classmates appear. Yayoi's approach reflects a complex blend of familial duty, professional ambition, and pragmatic adaptation to industry demands.