Kai

Kai is the father of Kalsang and the husband of Jinora.

Early life
Kai grew up as an orphan. When he was finally adopted by a nice family in 170 AG, he took advantage of their kindness by stealing their life savings and spent six months on the run from Earth Kingdom authorities.

Become an airbender
Following Harmonic Convergence, Kai soon discovered he possessed airbending. Soon after, he encountered Team Avatar, who was searching for airbenders to rebuild the Air Nation. He told them a false story on how his parents were killed by outlaws who were pursuing them, earning their sympathy and quickly being accepted in their company. Just as he boarded their airship, ready to depart, a sheriff and his deputies arrived, whom he falsely claimed to be outlaws. After Avatar Korra bested them, the sheriff revealed Kai's true identity as a thief. The boy attempted to run off with his loot, but was caught by Mako. The sheriff quickly took custody of the young lad, intending to send him to prison. However, in exchange for returning the life savings to Kai's family, Korra convinced the sheriff to allow Kai to turn over a new leaf with Team Avatar. Though the compromise was accepted, Mako warned Kai that he would be watching him, stating he knew the kind of person Kai was, due to having a similar past. Promising to change, the young boy turned to board the ship, where he gladly accepted Jinora's offer to teach him more about airbending, just before she blushed.