The yamabushi were warrior monks who lived up in the mountains. These monks were thought to have supernatural powers, because they resided in the mountains without any kind of comfort. If they were able to pass the tests that they were subjected to, then they could be reborn as Buddha and possess supernatural powers.
The yamabushi were equally as powerful as the samurai, as they were trained in different martial arts, not because they needed to protect themselves against mountain bandits, but to use martial arts as a way to prepare both mind and body.
Just like the ninjas and samurai, the yamabushi were surrounded by mysticism and shared land with the Tengu; demons living in the mountains which would sometimes adapt the form of an old yamabushi with a big nose.
The yamabushi are associated with ninjas, and it was believed that the monks would teach some of the ninjas their secrets regarding herbalism, astrology and medicine. In turn, they would share their knowledge with the ninjas of their clan.
Now we’ll take a look at what yamabushi means:
Yama is mountain.
Bushi is warrior.
The kanji for Yamabushi: 山伏
The first kanji means mountain 山
The second one means sleeping or laying down 伏
Yamabushi literally means: “the warrior that sleeps in the mountains”.
Also keep in mind that the word Yamabushi stems from the ancient monks that were called yama-hoshi which means “star of the mountains”.
The temples housed two types of monks; those who would learn spiritually and eventually accomplish important ranks in the future, and those who were simply workers. The latter would often cause problems and were known as Yama-hoshi from Mount Hiei and the Nara-hoshi from the temple of Nara.
Fun fact: hoshi means star and the yama-hoshi would carry a portable sanctuary of Hiye-Sanno, while the nara-hoshi carried the divine tree.