Kaya lived in a small town with her family in the Earth Kingdom. She met Sokka when Team Avatar stopped by the town in need of rest. Sokka made a comment that led her to believe that he was the Avatar. Sokka, wanting to date her, played along. The ruse continued as she introduced him to her family and showed him off to the locals. When the Rough Rhinos entered the town in search of the Avatar, they mistakenly captured Sokka, prompting Sokka's "sidekicks", Aang, Katara, and Toph, to defend the town while Sokka pretended to bend for the girl's benefit.
While Kaya was shopping at a small stand for fox furs, Team Avatar arrived on Appa, Aang's sky bison, needing a rest. They were trying on skins for fun when Sokka remarked to Aang that the skins "[looked] fabulous on [him]". Kaya, believing Sokka was talking to her, asked if he meant his compliment. Baffled, Sokka said that fake fur suited her, then asked her out. Insulted by his tone and poor choice of words, she threw the fake skin at him and walked off.
Sokka continued his attempts at impressing Kaya, telling her that he was an adventurer and asking if she had heard of the Avatar. The girl assumed he meant that he himself was the Avatar, and suddenly grew excited to meet him. Sokka played along with this, performing some simple yet impressive airbending moves, with the help of Aang. Delighted, she fell into his arms, and proclaimed that Sokka was her boyfriend, to Sokka's delight. The girl then took him to her house to introduce him to her family.
Even though she promised Sokka she would not tell anyone he was the Avatar, she could not resist and soon word spread to everyone. The locals immediately gathered, asking Sokka for advice which he uncomfortably yet proudly gave while the girl marveled at him. As Sokka feigned performing his bending abilities for the girl and the crowd, the Rough Rhinos entered the town in search of the Avatar. The girl watched as Sokka's "sidekicks", Aang, Katara, and Toph, supposedly "pretended" to bend and save the village in order to keep the so-called Avatar, Sokka, safe. She then walked up to Sokka and proudly kissed him, believing he had actually performed his sidekicks' bending from within the sack Kahchi put him in. As the two began walking off, Kaya asked how Sokka was able to do it, and was told that such a feat is not difficult for an Avatar. Aggravated, the "sidekicks" decided that it was time to show the girl who Sokka really was.
Based on her interaction with Team Avatar, Kaya seemed to be a fairly self-righteous, shallow girl, growing rather insulted when Sokka tried to ask her out. She was rather naive, as she readily accepted Sokka's claim that he was the Avatar and believed his "sidekicks" lacked bending abilities even after witnessing their displays of bending prowess. She seemed to be a generally cheery person.