Kai is an orphan who became an airbender after the Harmonic Convergence of 171 AG.[1] He was a mischievous thief who was eventually caught by the Dai Li in Ba Sing Se for using airbending,[2] but was later liberated from their control by Tenzin, who convinced him and the other new airbenders to train his skills and learn Air Nomad culture at the Northern Air Temple. As part of the Air Nation, he became a more honorable person, living to serve others by bringing peace and balance wherever possible. Sometime after 171 AG, he also entered in a romantic relationship with Jinora.[3]