Aya Oono operates as the 37mm gunner for Rabbit Team in Ooarai Girls Academy’s M3 Lee medium tank. This first-year student sports long dirty-blonde twin ponytails secured with black cords and brown eyes behind wide oval eyeglasses. She stands 150 cm tall, wears the standard Ooarai uniform with long black socks, and has blood type B. Her hometown is Kasama, Ibaraki Prefecture.

Aya energizes her fellow first-years with a bright, sociable personality. She obsessively engages in online communication via her cell phone, routinely receiving flirtatious requests and persistent demands for personal photos from male acquaintances. As a gunner, she acts impulsively—firing at every perceived target without awaiting commands or assessing threats.

During Rabbit Team’s reconnaissance near a crossroads against Anzio Girls High School, Aya spots two Semovente M41 tankettes. Mistaking them for decoys, she impulsively opens fire with the machine gun, revealing them as functional and forcing Rabbit Team into retreat under counterfire. The incident sparks crew arguments over fleeing or counterattacking. Later, under Azusa Sawa’s direction, she helps disable one Semovente using coordinated 37mm and 75mm fire.

Notable traits include her favorite tank (Hotchkiss H35), chosen flower (pansy), and an older brother. Her glasses frequently shatter during combat, especially after the M3 Lee takes hits; manga panels show her occasionally replacing intact glasses with broken ones post-impact to mimic damage. Her online interactions involve numerous male contacts making unwelcome advances. She shares a Japanese voice actor with Remi Takashima.