Hiroko Kanō is a central character in the romantic comedy series Ayaka is in Love with Hiroko. She holds the position of a senior sales manager at a company, where she is widely respected as a capable and competent boss by her colleagues and subordinates. Her professional demeanor is serious and professional, projecting an image of a dedicated and reliable team leader.

Outside of the workplace, however, Hiroko leads a different life. She is a lesbian and is known to be a womanizer at her local lesbian bar, where she is a regular patron. This part of her identity is a secret she keeps carefully guarded from her professional environment. The reason for this separation stems from a painful past incident at work, which forced her to remain closeted and build a "straight persona" to protect herself. As a result of this history and her own negative experiences, she has become highly cautious and assumes that the women around her, especially her coworkers, are all heterosexual.

This cautious nature creates the central conflict of the story. When her enthusiastic and much younger coworker, Ayaka Usagida, begins to pursue her romantically, Hiroko consistently misinterprets Ayaka's very direct advances. She dismisses them as either platonic friendliness, a misunderstanding, or believes Ayaka's affections are directed at a male colleague. This density is a key part of her personality, as she fails to recognize obvious confessions of love even when they are stated plainly. Hiroko’s primary motivation is to maintain her hard-won professional stability and avoid the vulnerability and potential fallout of a workplace romance, leading her to suppress her own growing feelings for Ayaka. She even goes so far as to reject Ayaka's confession while admitting she likes her back, rationalizing that it is for the best, and later pushes Ayaka towards another coworker.

Throughout the story, Hiroko’s role is that of the guarded love interest whose reluctance drives the plot. Her key relationships include her dynamic with Ayaka, which is a mix of professional respect and personal denial. She also has a supportive circle of friends at the lesbian bar, where she can be more herself, contrasting with her isolated demeanor at the office. Her character development is a gradual process of learning to confront her fears. Through Ayaka's persistent and sincere efforts, Hiroko is slowly inspired to live more courageously and freely, eventually beginning to dismantle the walls she built around her heart. She does not possess any notable supernatural or physical abilities, with her strengths lying in her professional competence and, ironically, her obliviousness to romantic pursuit.