Ruon-Jian was a teenage boy who lived on Ember Island, alongside his childhood best friend, Chan. Much like his friend, he was confident and conceited, and acted like a jaded rock star. He often communicated with just a flip of his hair or a subtle shrug. He was part of the Fire Nationelite on Ember Island.
In the summer of 100 AG, Zuko, Azula, Ty Lee, and Mai arrived on Ember Island, Ruon-Jian and Chan were impressed by Ty Lee and Mai's appearance and skill during a game of kuai ball. Chan invited Ty Lee to attend the party he threw at his house that evening and Ruon-Jian extended the invitation to Mai. Azula managed to convince Chan to invite herself and her brother, with the approval of Ruon-Jian.
Arriving early at the party, Ruon-Jian gave the foursome a warm welcome, much to Zuko's annoyance. The prince of the Fire Nation acted jealously on his comment, asked Mai what she thought of him, and accused her of liking him after, saying that she did not have any opinion about him. Later, Zuko's irritation was increased to a breaking point when he saw Ruon-Jian talking with Mai after he had left to get her some food. The jealous Zuko quickly intervened by pulling Ruon-Jian away from Mai. After he fixed his hair, Ruon-Jian tried to reason with him by telling him that he should relax as it was "just a party". Zuko did not take this comment well and he pushed him into Chan's nana's vase. As Zuko left the party, Ruon-Jian taunted him by calling him a "loser boy".