Miyabi Takaoka attended kindergarten with Ao Horie before enrolling at a separate all-girls high school. There, she won a school pageant, cementing her popularity. Outwardly assertive and flirtatious, Miyabi possesses a strong personality layered over an underlying innocence.

She met Takumi Kijima at a mixer and found herself captivated by his sincere feelings for Ao, even urging him to contact her. Though Miyabi developed her own romantic interest in Takumi, her efforts to attract him failed. This led her to exchange contact details with Ao instead, becoming Ao's sole female friend. Miyabi then inserted herself into Ao and Takumi's developing relationship.

During the "Adult Arc," Miyabi confronts Ao at university, bluntly labeling her a "scumbag" while voicing hope for Ao and Takumi's breakup—a clear sign of her lingering feelings for Takumi. That summer, accepting Hanasaki Horie's invitation, she visited Hakata and reunited with both Ao and Takumi.

The eldest of four siblings, Miyabi aspires to be a writer and shares her literary pieces with Souichiro Yabe for critique.