Ayumi is a first year student from Ooarai Girls High School. She operates the sponson-mounted 75mm gun of the Rabbit Team's M3 Lee. She comes from Omitama, Ibaraki.
Ayumi is a girl with a long dark blue hair and a pair of dark blue eyes. Her official artwork as well as many snapshots in the anime show a few freckles on her cheeks.
Ayumi is noted for her boyish personality. As stated in her artwork, this also "causes her to have more stress". Despite her tall and somewhat more developed physique (in comparison with the rest of the team), she is usually shown to be just as youthful and carefree as most of her teammates.