Aki Mikage is a first-year student at Yezo Agricultural High School, where she is enrolled in the Department of Dairy Science and is an active member of the Equestrian Club. She is the only child of the Mikage family, which has operated a farm in the Hokkaido countryside for over four generations. Growing up in this environment, she learned the basics of farming and livestock care from a young age. She has a deep fascination and love for horses, having been part of an equestrian club in her town.

In terms of appearance, Aki is a girl with short, purplish-black hair that features a small, distinct ahoge on the right side, with bangs hanging on the left. She has wide eyes of the same purplish-black color. She is typically seen in the standard female school uniform. During practical class sessions or when working on the farm, she wears a jumpsuit, and when horseback riding, she wears an English equestrian outfit.

Aki has a kind and sincere personality, but she is often described as a non-intellectual type. Her academic performance is notably poor, particularly in subjects like history, and she can be dense when it comes to sensing the emotions or intentions of those around her. This dense nature extends to her romantic life, as she is initially unaware that several boys are interested in her. However, when it comes to horses and horse-related subjects, she demonstrates great focus, aptitude, and talent, particularly in horseback riding. She grew up speaking a local dialect and was once ashamed of it, making an effort to suppress it by the time she entered high school.

Her primary motivation is her love for horses and her desire to pursue a career related to them. This puts her in direct conflict with her family's expectations, as they have been grooming her to inherit the family farm. Initially, she resigns herself to this fate, but a significant turning point occurs when a classmate helps her reveal her true feelings to her family. The family reluctantly agrees to support her dream of studying horses on the condition that she graduates from college. Because this intervention disappointed her family, the classmate who helped her promises to be her tutor until she gains admission to a specific agricultural college. Aki's role in the story is central to the protagonist's life at school and his personal growth, as she is the one who introduces him to the Equestrian Club and becomes a close friend.

Key relationships include her bond with her childhood friend and neighbor, which is a source of closeness for her. Her relationship with the protagonist is initially friendly, and she is often oblivious to his romantic feelings for her. Her classmates sometimes have to explain social or romantic situations to her for her to fully understand them. Over time, she realizes she has developed romantic feelings for him, a realization that stems from his support in helping her confront her family about her dreams. Her father is very protective and wary of any boys getting close to her.

Throughout the story, Aki develops by moving from a state of resigned acceptance of her predetermined future as heir to the family farm to actively pursuing her own passion for horses. Her emotional expressions become more varied as she grows closer to her peers, and she eventually acknowledges her romantic feelings. Her notable abilities include practical farming skills such as livestock care, processing chickens, making bacon, milk and cheese processing, and driving a truck. Her most prominent talent is her skill in horseback riding, an area where she shows great focus.