Aoma was an earthbender, farmer, and the daughter of the village captain of Yokoya. In her youth, she was among those who regularly harassed a local servant girl, Kyoshi, due to her closeness to the suspected Avatar, Yun, despite her status as outsider and orphan.
Aoma was born to the village captain of Yokoya and her husband around 312 BG. As a result, she was the ideal age to be the possible successor of Avatar Kuruk. When masters Jianzhu and Kelsang visited Yokoya in 305 BG, Aoma was among the Earth Kingdom children presented with the Avatar relics, but she failed the test, much to the annoyance of her mother.
Growing up, Aoma learnt some basic earthbending techniques to help her parents with the farm work. Over time, she came to bully Kyoshi, an orphan who had become a servant at the Avatar mansion that had been built in Yokoya to house Yun, the earthbender identified as Kuruk's successor. Aoma was jealous of Kyoshi's friendship with Yun and the comparatively good life she had at the mansion, while she had to toil on her parents' fields.
In 296 BG, Aoma and her friends Suzu and Jae held up Kyoshi outside the mansion as she was delivering a jar of pickled spicy kelp. Using her earthbending, Aoma took the jar from Kyoshi and floated it in the air while taunting the servant. Realizing that this was a chance to get into contact with Yun, Aoma declared that she would "help" Kyoshi by transporting the jar to the Avatar mansion. This plan fell through, however, when the group was stopped by Rangi, Yun's bodyguard and a friend of Kyoshi. Aoma first attempted to make excuses and use her charm in order to convince the firebender to let her through, but Rangi remained unswayed and ordered them to leave the grounds of the mansion. Angered, Aoma launched the jar far into their air in defiance of Kyoshi and Rangi before fleeing back to the village.