Nao Mashiba is a high school student and one of the main characters in the story. She was an active member of the soccer club during middle school, reflecting an athletic background, but after entering high school she no longer participates in sports and instead develops a strong enthusiasm for the boys-love genre of fiction. She possesses a mature and composed demeanor on the surface, yet she is actually a tomboy who struggles to present herself as more feminine. Any mention of her tomboyish traits embarrasses her easily, and she finds it difficult to express herself in such situations. She often serves as the straight man in conversations but also has a playful side that indulges in absurd jokes. She frequently argues with her friend Mao Kurokawa, who teases her about her boyish behavior. Nao uses the first-person pronoun "boku," which carries a masculine tone, and while she sometimes tries to switch to the more feminine "watashi," she habitually defaults to "boku." She is the largest-chested member of her friend group, a detail that Mao occasionally points out. She wears glasses and has blue hair and blue eyes. Her role within the group is often that of the relatively sensible member, though her own quirks—especially her devotion to boys-love stories and her tendency to become flustered—provide comic relief. Over the course of the series, she participates in typical high school events alongside her friends, such as the culture festival, where she initially planned to enter the beauty pageant but caught a fever, prompting her friend Wakaba to take her place. Her development is subtle, involving a gradual acceptance of her own nature and a deepening bond with her classmates. Aside from her past athleticism, she does not display any extraordinary abilities or skills; her most notable traits are her fandom for boys-love media and her role as a source of humor and warmth within the group.