A syncretic mountain religion of Japan blending the Mikkyo teachings of esoteric Buddhism (Shingon and Tendai sects), Tibetan Mysticism, and indiginous Japanese Shinto and folk religions emphasizing Nature worship. The religion has its earliest inception in the 7th century by En no Gyoja (En the Ascetic). Followers are called Shugenja and often synonymous with ascetic mountain warriors called yamabushi, "those who dwell in the mountains". As well, because of their garb and historically secretive lifestyle, they are frequently associated with the infamous Ninja.

Shugenja and Yamabushi (often incorrectly translated as "mountain warriors") were frequently very adept fighters. The history of Shugenja's and yamabushi's fighting ability and secretive lifestyle, as well as the ninja's use of yamabushi religious garb to travel in disguise have blurred the lines between ninja, yamabushi, and Shugenja.

Modern day Shugenja still exist in Japan and throughout the world. Pilgrimages involving mountain treks and performance of austere faith-testing rituals such as walking across burning coals and prolonged cold water immersion while reciting Sutras and confessing sins and weaknesses are still performed. Outside these rituals, Shugenja are in all walks of life and att...