Emma is a pilot of the Kotobuki Squadron, operating a blue Hayabusa fighter adorned with her personal emblem: a blue scythe hovering above a white rose, with rose thorn patterns decorating the rear fuselage and wingtips. She has blond hair that is typically secured in a French bun by a white rose pin on her right temple, though she sometimes wears it loose to waist length, and her attire consists of a blue and gold ensemble with a blouse and brown gloves that extend to her biceps.

Emma presents an outwardly refined and aristocratic demeanor, speaking with noble grace and favoring tea rituals. This elegant facade, however, contrasts sharply with a cynical core that is prone to snide remarks and passive-aggressive insults. Fueled by past financial hardship, she is an extreme miser who prioritizes thriftiness, recoils from waste, and maintains spartan habits. Despite these flaws, she never directs them toward her squadron allies, instead exhibiting patience and kindness, particularly toward her childhood friend, Kirie, who she supports during times of distress.

Emma hails from a once-wealthy noble family in Rahama, which was ruined by her parents' financial mismanagement and vulnerability to scams. To support her family, she became a mercenary, hiding this occupation from her parents, who believe she is traveling luxuriously. She sends most of her earnings home, inadvertently funding their continued wastefulness, and intercepts fraudsters who target them without confronting her parents about the underlying issue. Her primary motivation is to restore her family's former estate, having already repurchased their house and a rare Rahama sakura tree, which she tends meticulously.

Within the story, Emma participates in every mission of the Rahama Campaign, providing tactical insights and mocking adversaries such as Adolfo of the Nazarin Squadron. When Elite Industry pirates invade Rahama, her personal history drives her to fierce resistance. She publicly berates the mayor for capitulating, rallying the townsfolk to defend the city. She is shot down by the pirate leader in the ensuing skirmish but survives an emergency landing. Her aggressive pursuit of targets and sharp observational skills earn her the moniker "Emma the Fierce."

Emma shares a key relationship as childhood friends with Kylie, another member of the squadron. In combat, she demonstrates tremendous discernment and observation skills, enabling her to pick up on enemy pilots' habits and flight patterns. Once she identifies an opponent as a target, she will chase them relentlessly. In combat, her pupils narrow to slits during target fixation, and hidden anger fuels her volatile but effective combat style.