Rangi was a Fire Army officer and firebending instructor who was the only child of Junsik[10] and Hei-Ran,[11] Avatar Kuruk's former firebending teacher. Born into the illustrious Sei'naka clan, a noble family that had taught members of the Fire Nation Royal Family firebending for generations,[5] Rangi was rigorously trained as a Fire Nation soldier and eventually appointed as a bodyguard to Yun, the falsely identified Earth Kingdom Avatar. She became close friends with him and Kyoshi, who was his servant at that time. After Kyoshi's identity as the true Avatar was revealed, Rangi fled with her into the inner Earth Kingdom, where they joined the Flying Opera Company, and Rangi began to train Kyoshi in the art of firebending. In 296 BG, the two began a romantic relationship with each other, though they parted ways in order for Rangi to save her mother from a lethal poison.[12] The following year, Kyoshi and Rangi reunited during the Festival of Szeto, and worked with each other and their allies to put an end to the escalating Camellia-Peony War.[13][14] Rangi fiercely fought by Kyoshi's side during her lover's final confrontation with Yun, and though she was terribly wounded, she was successfully healed by the Avatar. Rangi promised to stay by Kyoshi's side, no matter what.[15]