Ayano Sugiura is the diligent and hardworking vice president of the Nanamori Middle School student council, who takes her academic and administrative duties very seriously. She consistently ranks among the top students in her year but is frequently frustrated by her perceived academic rivalry with Kyōko Toshinō, who earns high scores without apparent effort.

She exhibits a tsundere personality, particularly concerning Kyōko Toshinō, for whom she harbors romantic feelings that she initially struggles to acknowledge or express honestly. This leads her to become flustered, embarrassed, or hostile in Kyōko's presence. Over time, especially from the third season onward, she gradually develops more confidence and becomes somewhat more open about her affections.

Physically, Ayano is notably tall, standing only slightly shorter than Yui Funami. She has long maroon hair, typically tied in a ponytail reaching the middle of her back, with bangs covering most of her forehead. Her eyes are purple. In the first anime season, she wore tights with her school uniform. Outside of school, she prefers colorful and fashionable clothing.

A quirky aspect of her personality is her tendency to make puns based on famous location names, such as "Bakkin" for Buckingham or "Nai nai" for Niagara. These often amuse Yui Funami, who laughs upon hearing them.

Her relationships are central to her character. Chitose Ikeda is her best friend and confidante; Ayano frequently seeks her advice about Kyōko, and Chitose often imagines romantic scenarios involving them. Ayano's relationship with Kyōko Toshinō is defined by unrequited love and academic rivalry; she almost exclusively uses Kyōko’s full name and displays her most pronounced tsundere reactions around her, while Kyōko remains largely unaware of Ayano's feelings. She shares mutual respect with Yui Funami, and they once briefly entertained the idea of being sisters after Kyōko suggested it. She also maintains generally positive interactions with others, such as appreciating Sakurako Ōmuro's curry and gently brushing Sakurako's hair as she fell asleep.

Across various media, including the main series, OVAs like *Nachuyachumi!*, and spin-offs such as *MiniYuri* and *Tensei Shitara Akari dake Slime datta ken*, her development is shown through gradual change. She evolves from being easily flustered and in denial to slowly becoming more proactive in seeking interactions with Kyōko and participating in group activities with the Amusement Club, indicating growing self-assurance.

Her favorite foods are crème caramel and pudding, which she often stores in the student council refrigerator, though they are frequently stolen by Kyōko or Sakurako Ōmuro. Her given name, Ayano, combines the characters for "design" and "from," while her surname, Sugiura, means "cedar" and "bay" or "inlet."