Miyako Shikimori, nicknamed Micchon, underwent significant personal change. In middle school, she kept her hair short, dressed masculinely, practiced martial arts, and competed with her older brother Fuji, often being mistaken for a boy. Before high school, she consciously transformed her appearance and demeanor, growing out her pink hair and adopting traditionally feminine clothing and mannerisms inspired by shojo manga to match her desired self-image. Her family includes her mother Miyabi, brother Fuji, and an absent father with undisclosed circumstances. This childhood established her initial tomboyish traits and later efforts to redefine her gender expression.

Her personality blends confidence, kindness, and competitiveness with vulnerabilities. She shows deep care, especially for her boyfriend Yuu Izumi, relentlessly protecting him from chronic misfortune, a protective instinct extending to others in need. She experiences visible jealousy when Izumi admires other girls or media figures but channels this into supportive actions, like comforting a romantic rival. Competitiveness surfaces in sports, games, or situations involving Izumi's attention. Flaws include neglecting her glasses for poor eyesight, being tone-deaf, initial culinary ineptitude (later improved through lessons), and occasional social awkwardness like overanalyzing outfits or interactions with Izumi. She adheres to personal principles, such as addressing Izumi by his last name only, emulating her grandparents.

Relationships define her. Her bond with Izumi is central, marked by mutual affection and her role as his physical protector. His encouragement enhances her athletic performances. Interactions with friends Kyou Nekozaki, Yui Hachimitsu, and Shuu Inuzuka reveal a supportive circle; she shares a brotherly rapport with Inuzuka, accidentally calling him "nii-chan." She is popular across genders, with female classmates admiring her coolness or attractiveness. She comforted classmate Ai Kamiya over unrequited feelings for Izumi, leading to a friendship-focused outing Kamiya processed emotionally. Familial relationships show closeness with her brother and mother, though home life discussions remain minimal and occasionally uncomfortable.

Physically, she has long, flowing pink hair (shorter in middle school and later during university), blue-green eyes, and a slim build. High school typically shows her in the standard uniform: white shirt, black sweater, gray skirt, navy blue knee-length socks, and brown shoes. University epilogue sequences depict a mature style with shorter hair. Her "cool mode" during protective or athletic moments features sharp eye expressions and heightened prowess, contrasting her usual cute demeanor characterized by blushing or cheek-puffing when flustered or annoyed.

Character development progresses from her intentional high school image change to growth in skills like cooking and emotional openness. The narrative reveals past shyness before dating Izumi, showing how their relationship bolstered her confidence. Later story arcs, including the university epilogue, confirm her sustained relationship with Izumi and a return to shorter hair, signifying comfort with her identity beyond high school conventions. Key events include sports festivals where Izumi's support unlocks her peak abilities, cultural festivals demonstrating group cohesion, and a school trip to Kyoto where she helps a withdrawn classmate.