Mai Asahina attends Hakujō Academy as a student in Yūto Ayase's class. She exhibits a quiet and reserved personality, frequently contrasting with her energetic friend Ryōko Sawamura. Her demeanor reflects Miko-like composure, contributing to an image of kindness and tranquility. This elegant poise combined with her gentle nature attracts male students, resulting in her nomination for a school beauty pageant.

She holds the position of vice-chairman in the school's naginatajutsu club. Her closest friendships are with Shiina Amamiya, another skilled practitioner of naginatajutsu and piano, and Ryōko Sawamura. Mai, Shiina, and Ryōko form a frequent trio, with Mai and Ryōko often supporting Shiina regarding her feelings for Yūto.

Mai debuted in brief cameos during the anime's first season. Her role expanded significantly in "Haruka Nogizaka's Secret: Purezza," where she became a regular supporting character.