Aria was a wealthy girl whom Tatsumi met in the Capital of the Empire. She harbored a dark family secret, despite her kind and cute appearance. Aria was a cute, young girl. She had blonde, shoulder-length hair topped with a fluffy, light blue accessory and blue eyes. She wore a white, long-sleeved shirt with a light blue ribbon on her neck. Above her shirt, she wore a sleeveless, light blue dress with a black bodice and white frills. Aria also wore a pair of white boots. Aria initially appeared to be a very kind, optimistic and caring girl, but this was just to disguise her true nature. In reality, like her parents, she was murderous, cruel, maniacal, ruthless, twisted and sadistic, enjoying picking on peasants, and then painfully torturing them until they died. Coming from a wealthy family, both enjoyed a luxurious style of life. The father was often seen wearing pricey suits, while the mother donned silk dresses. torturing and killing naive and trustworthy citizens that they took in, predominately people from the countryside who sought out a better life in the Capital. Aria's mother thoroughly described their methods of torture that were used on their victims as an evening hobby, which she very much enjoyed. At some point before the start of the series, Aria's parents took in Sayo and Ieyasu as their guests by Aria where the two were later brutally tortured and infected by Lubora disease that eventually killed Sayo and left Ieyasu still alive through his willpower.

When Tatsumi was taken in by Aria, her parents welcomed him into their residence. The following evening, Aria's family and their guards were targeted under a contract hit by Night Raid. The mother was bisected by Sheele and the father had his neck broken by Leone.