Akatsuki Minami attends Rakurou Private High School alongside classmates Mizuto Irido and Yume Irido. Her family lived next door to Kogure Kawanami's during childhood, forging a close elementary school bond that later turned romantic throughout middle school. Kogure's stress-induced hospitalization, stemming from Akatsuki's intense affection, led to their breakup. Despite this, they continue to clash in frequent arguments, their connection defined by unresolved tension.

Outgoing and confident, Akatsuki typically presents a cheerful, sociable front. She easily strikes up conversations and shows genuine concern for others. However, remarks about her petite figure, especially her chest size, trigger visible insecurity, causing defensive reactions or physical contact with female friends like Yume as a frustration outlet. She demonstrates strong determination in pursuing goals, initially planning to marry Mizuto to become Yume's sister before abandoning the idea and forming a platonic friendship with him instead.

Yume Irido is her closest friend; Akatsuki actively supports her, offering advice during personal struggles. She also befriends Isana Higashira after Mizuto rejects Isana's romantic feelings, creating a supportive group dynamic.

Physically, Akatsuki is notably short. She has light brown hair, usually styled in a ponytail secured with a black ribbon, and blue eyes. Fashion-conscious, she keeps up with trends and skillfully applies makeup. Her attire typically reflects a standard high school student's style, often seen in her school uniform.