Kanako Miyamae is the protagonist of her story, a second-year high school student who transfers to the all-girls Catholic academy Ame no Kisaki. Her decision to attend this specific school is a romantic one, as it is the same institution where her parents first met and fell in love. However, Kanako has a deeply personal motive for seeking a partner in a single-sex environment: she possesses a severe and inherent fear of men, a condition that manifests as a physical reaction. Upon any physical contact with a male, she immediately breaks out in painful hives. This trauma is rooted in an incident during elementary school when a piece of her recorder and her physical education uniform were stolen, an event she associates with boys. Consequently, her quest is not for any romantic partner, but specifically for a same-sex relationship, or her "fated yuri partner".

In terms of appearance, Kanako is a notably tall girl, with her height being a point of insecurity as it stands around 173 centimeters; this stature often makes her the target of teasing from other characters. She has neck-length blue-black hair and blue eyes. Her personality is one of high energy and intense, often frantic, romantic and sexual fantasy. She has a habit of beginning her internal reflections on her situation with the phrase "Dear mother in heaven". While her goal is to find true love, her immediate reactions to attractive girls are overwhelmingly physical, most famously resulting in massive, spontaneous nosebleeds, a running visual gag that indicates her perverse excitement. She is openly and exclusively interested in girls, to the point of keeping a personal album of nearly every female student at the school. Despite being the protagonist, she is not portrayed as particularly capable; she is known for being a poor student, having made history as the first Ame no Kisaki student to fail every subject.

The core of Kanako's role in the story is defined by her relationship with Mariya Shidou. On her first day at school, she meets Mariya, a beautiful and graceful girl who seems to be the perfect romantic partner. However, this ideal shatters when Kanako discovers that Mariya is, in fact, a sadistic and sarcastic boy who is cross-dressing to attend the girls' school. Mariya immediately leverages this situation against her, threatening to frame Kanako for a sexual crime if she reveals his secret. To ensure her silence, Mariya becomes her new roommate, forcing Kanako to live in constant, tormenting proximity to the boy she finds both repulsive (because of her allergy) and alluring (because of his feminine appearance). This creates a central irony: despite knowing his true gender, Kanako frequently falls into his traps and succumbs to her attraction to his feminine charms.

Kanako's other key relationships are shaped by her interactions with the eccentric student body. She is looked after by Ryuken Ishima, the dormitory leader and most popular girl in school, who has vowed to protect her. She also considers girls like Sachi Momoi and Yuzuru Inamori to be her friends, though her perverted fantasies often color her view of them. Nagging her constantly alongside Mariya is his cold and sharp-tongued maid, Matsurika Shinōji, who never misses an opportunity to insult Kanako with nicknames like "Ms. Pig" or "Torre Eiffel" due to her height. Despite her awful living situation and constant harassment, Kanako shows little character development or maturity; she remains unchanging in her overwhelming, stereotypical perversion and her single-minded, if perpetually thwarted, quest for a girlfriend. She has no special abilities beyond her unusual physical reactions; her primary notable traits are her allergy to men, her cataclysmic nosebleeds, and an almost useless talent for cooking, being able to "probably burn instant noodles to an edible level".