Kaizhai (開齋) Air Nomads are ethnic Air Nomads who conceal their origins, their airbending, and often their religion in response to the Air Nomad Genocide. Descending from the survivors of the Air Nomad Genocide, they can be found scattered throughout the Earth Kingdom and, to some extent, also in the Northern Water Tribe, continuing to hide from the Fire Nation. Kaizhai communities vary in the level of secrecy and degree of true or pretended assimilation they have undergone.

Unsurprisingly given their lack of safe contact with each other, Kaizhai groups are very diverse. Some continue to practice the Air Nomad religion openly in the Earth Kingdom or Northern Water Tribe, which is not particularly distinctive insofar as, particularly in the Northern and Western Earth Kingdom, there are significant populations of people who are of non-Air-Nation descent but who are believers in the Air Nomad religion as taught to them by missionaries. In this context, Kaizhai Air Nomads simply adopt the outward dress and local peculiarities of their local coreligionists. With this practice involving little moral distress, these people have often completely integrated into their new settled communities and have often deliberately chosen to intermarry with those of different ethnicities but shared religious beliefs. Knowledge of the secret Air Nation heritage of some community members is kept secret from outsiders, but within it, trusted people may know. As the Fire Nation has sometimes persecuted non-Air-Nation practitioners of the Air Nomad religion, though, their position is considered relatively precarious, and they have usually fled in advance of the Fire Nation invasion when their communities are in its way.