Kokona Minowa is a first-year student at Aokisora High School who serves on the library committee and works in the school library. Her surname, Minowa, incorporates the characters for "increasingly," "rear/behind," and "ring/circle," while her given name, Kokona, signifies "nine." She possesses black hair and violet eyes.

Her interactions with fellow students occur mainly within the school setting. During one incident, she walks past a confrontation involving Natsu Asumi and athletic club members; her books scatter, leading Haruki Mishima to assist her. Her most defined connection is with Natsu Asumi, a track and field athlete. She exhibits quiet concern for him, demonstrated by leaving food at his door when he is ill and intervening during student confrontations. These quiet actions hint at unspoken feelings, though their dynamic remains largely unexplored.

Kokona appears sporadically throughout the series. After initial scenes, her involvement decreases significantly, and she receives minimal focus within the overarching plots.