Ayame Minamikujō is introduced as a childhood friend of Aki Mikage, one of the main characters. She first appears during an equestrian competition that the students of Yezo Agricultural High School participate in, and she becomes a recurring figure from that point onward. Her background is that of a competitive girl from a privileged family who attended the same middle school as Mikage. Her defining trait is her self-declared rivalry with Mikage, which forms the core of her identity within the story. She harbors a significant amount of resentment and jealousy, not only because Mikage attends Yezo Ag while she does not, but also specifically toward the protagonist, Yugo Hachiken, whom she believes has taken the place at the school that rightfully belonged to her.

Her personality is loud, boastful, and marked by extreme overconfidence that is rarely backed by skill or understanding. She embodies the archetype of a wealthy ojou-sama character, complete with a haughty and suffocating laugh. Her ego is immense, and she possesses a complete lack of self-awareness, which makes her oblivious to her own ridiculousness. Despite these annoying traits, she is not portrayed as a genuinely malicious person. Her pretentiousness is so exaggerated that it becomes a primary source of comedy, often leaving other characters exasperated but not truly angered. She has a habit of referring to Hachiken by random numbers instead of his name, demonstrating her dismissive attitude toward him, yet her interactions with Mikage reveal a more complex, almost affectionate side.

Her primary motivation is to be a rival to Aki Mikage. This desire drives most of her actions, from taking up horse riding and founding an equestrian club at her own school just to compete against Mikage, to declaring that she will also attend college simply because Mikage intends to. Her rivalry is less about genuine enmity and more about maintaining a connection to Mikage, whom she clearly admires. She frequently compliments Mikage's abilities and expresses strong faith in her, even when she is abrasive towards others. Her role in the story is largely that of comedic relief and an instigator. She serves as a foil to the more grounded and kind-hearted Mikage and as an amusing antagonist to Hachiken, constantly dismissing him while also being a source of pressure and chaos.

Her most significant relationship is, of course, with Aki Mikage. While Mikage remains unfazed by Ayame's rivalry, treating her with genuine warmth and friendliness as an old friend, Ayame interprets this as a challenge. She also has a key relationship with Yugo Hachiken. She views him as an unworthy rival and a usurper, and she goes out of her way to be difficult and condescending toward him. However, in moments of crisis, such as when Hachiken collapses from overwork, Ayame does not hesitate to offer her help, revealing a practical and reliable side beneath her pompous exterior. Her interactions with other members of the equestrian club are generally marked by her attempts to assert superiority, which are typically met with confusion or amusement.

Over the course of her appearances, Ayame shows a notable development. While she remains largely boastful and comedic, the story reveals that her confidence is not entirely hollow. Her determination is genuine, and her faith in Mikage is consistently shown to be well-placed. She evolves from a simple one-note rival into a character who, despite her flaws, is a loyal and supportive friend in her own peculiar way. Her initial resentment toward Hachiken also softens slightly as she comes to recognize his efforts, even if she would never admit it openly. Her abilities are almost exclusively tied to her equestrian pursuits, though she is portrayed as being less skilled than Mikage and often ignorant of the official rules of competition. Her true notable ability is her unwavering, if misplaced, self-confidence and her capacity to annoy and energize those around her in equal measure.