The Tiji festival is a three-day ritual known as "The chasing of the Demons" and it is centered around the Tiji myth. Tiji tells the story of a deity named Dorje Jono who must battle against his demon father to save the Kingdom of Mustang from destruction. The demon father wreaks havoc on Mustang by creating a water shortage which, in this extremely arid land, is the most precious life-sustaining resource. Dorje Jono eventually defeats the demon and banishes him from the land.

Tiji is a celebration and reaffirmation of this myth. Throughout the festival the events and story of the myth are re-enacted. The festival is timed to coincide with the end of the dry season (late winter/spring) and ushers in the wetter monsoon season. Tiji comes from the words "ten che" meaning "the hope of Buddha Dharma prevailing in all worlds" and is a spring renewal festival that also celebrates the triumph of good over evil. In 1964 Michel Peissel was the first westerner to observe the Tiji festival. At this time, the Mustang region was still completely closed off to foreigners and he had to obtain special permission from the government of Nepal in order to enter the region. Despite his arrival on the last day of the celebration (he was unaware of the observance of Tiji) the experience left a lasting impression on him. "The scenes I witnessed were so extraordinary and so unexpected that I dared not believe my eyes and even today I have some trouble in believing in the reality of what I saw that day."