Mai Inose is a second-year student who joined the geology club after seeing Mikage Sakurai present a geological map near the club room, sparking her fascination with geology as an extension of her geography interest. Her significant admiration for Mikage often influenced her early club activities. She later became part of the merged Earth Sciences Club, serving first as treasurer before stepping up as club president after Mari Morino stepped down.

At 145 centimeters tall, she is the group's shortest member. Mai exhibits a cheerful and energetic personality, though she can be clumsy or absent-minded, especially when deeply engrossed in her hobbies. One such hobby is personally exploring maps to seek out enclaves and culverts; this intense absorption sometimes leads to her getting lost. Her enthusiasm for map-related topics is notable, often causing her to talk at length, though separate from official club activities. She dreams of creating her own map.

She faces challenges with photography, her photos frequently turning out blurry. Academically, after becoming president, she set a new goal of participating in the International Earth Science Olympiad. Her leadership role reflects a strong sense of responsibility toward club objectives and member development.

In relationships, she developed a crush on Sayuri Ibe, president of the newspaper club, whom she prefers to call "Eve." This personal aspect doesn't dominate her arc. Within the Earth Sciences Club, she is supportive, particularly toward younger members like Mira Konohata, who nicknames her "Ino-senpai" or "Ino-chan."

Mai develops from an enthusiastic geology newcomer into a proactive leader focused on club cohesion and her academic ambitions, balancing her map-making hobby with her responsibilities.