Mimina Osawa attends Hakureiryō Academy, hailing from Japan's prestigious and influential Osawa family. Despite her wealth, she remains friendly and approachable. Her appearance is notably childlike, with a small stature belying her 19 years, attributed to extended hospitalization during her formative years for an unspecified illness.

During prolonged hospital stays, she cultivated drawing to combat boredom, evolving into a significant skill. She developed a strong preference for creating art solely from personal inspiration, harboring a distinct aversion to fulfilling external demands or commissions.

She initially dislikes fellow student Akiharu Hino. However, her feelings shift positively after he intervenes when other students pressure her about her art, publicly defending her right to draw purely for her own enjoyment. This leads her to develop affectionate feelings toward him.

Her personality blends a desire for social acceptance with individualistic tendencies. She values her family's reputation and actively works to uphold its dignity. Despite her youthful appearance, she exhibits maturity through leadership capabilities, often taking charge of school events and activities. Her willingness to assist peers contributes to her respect among classmates.

Characterized by a complex inner world, she balances her privileged status with genuine kindness. Her background of illness-induced isolation contrasts with her later sociable nature at the academy. She navigates school life while managing expectations associated with her family name, demonstrating both resilience and adaptability.