Ayame Moriya is a student at Eimei Senior High and the younger sister of Karen Moriya, who is the girlfriend of Kengo Haryu and a close friend of Chinatsu Kano. She is in the same academic year as the protagonists Taiki Inomata and Hina Chono, and is placed in class 2-A during her second year. Ayame serves as the team manager for the Eimei High badminton team, a role she assumed somewhat suddenly after the school's cultural festival. Her motivation for taking the position was not purely a love for the sport, but rather an interest in getting close to a particular boy in the club.

In terms of appearance, Ayame is recognized by her distinctive black hair styled into twin tails and her noticeable double tooth. She has a tendency to wear her school uniform in a deliberately loose, disheveled manner, a choice that often accentuates her figure.

Ayame possesses a vibrant, outgoing, and free-spirited personality. She is exceptionally candid and outspoken, rarely hesitating to voice her opinions directly and often addressing others by nicknames. Her approach to romance is notably pragmatic and light-hearted; she is a self-described matchmaker who believes love should be simple and enjoyable. She famously operates under the philosophy that it is happier to be the one who is loved than to be the one who falls in love. Consequently, she is open to dating boys who show interest in her, provided they meet her standards, but she is also known to end relationships abruptly over minor issues, a behavior that has earned her a reputation for being fickle. Despite her carefree exterior, she dislikes leaving things ambiguous and can be surprisingly pragmatic and detail-oriented, especially when her actions impact others. She also has a strong aversion to perspiration and an intense fear of insects, particularly spiders.

Ayame's primary role in the story is as a catalyst for the romantic subplots involving her peers. While her provocative demeanor and rumored history of many ex-boyfriends initially lead some to expect her to be a rival or a "sexy catalyst" for Taiki, she subverts this expectation by showing no romantic interest in him whatsoever. Instead, upon discovering that her friend Hina Chono harbors unrequited feelings for Taiki, Ayame enthusiastically adopts the role of a "shipper on deck" and declares herself a supporter of determined girls. She actively involves herself in trying to help Hina win Taiki's affections, though her well-intentioned schemes and attempts to play matchmaker often prove to be misguided or backfire. Her bluntness and forceful encouragement, while intended to be helpful, highlight her belief that she can bring a romance into existence through sheer will, a flaw that leads to complications. When Taiki ultimately rejects Hina, Ayame does not hesitate to voice her displeasure and complain to him directly, demonstrating her loyalty to her friend.

Through her persistent, if flawed, efforts to support Hina, Ayame's character undergoes a subtle development in the eyes of both her peers and the audience. Her initial reputation as a promiscuous and shallow individual gives way to a more nuanced understanding of her as a caring, earnest, and surprisingly conscientious friend, even if her methods are unorthodox. Her role as team manager also showcases a more responsible side, as she becomes an important support for the club members, with her ability to assist the male athletes being noted as particularly effective. Ayame's key relationships are defined by her family connection to her sister Karen, her friendship and supportive dynamic with Hina Chono, and her purely platonic acquaintance with Taiki Inomata, whom she considers entirely outside of her romantic interests.