Both Mikkyo and Tengu were of importance within some older koryu schools.
Mikkyo was a type of esoteric Buddhism,
often associated with the Shingon and Tendai sects. They were both important influences to the teachings of Shugendo, a type of ascetic-esoteric Buddhism with a belief in supernatural powers.
Tengu were mythological mountain and forest creatures, which could perhaps be compared to our wetts. They have still an important place in Japanese culture. Among other things, Tengu festivals are organized in today’s Japan. Tengu was demon-like, had magical powers and immense skill in the art of the sword. From the beginning they were depicted as
humanoid birds or foxes. After the Middle Ages, they were depicted as long-nested mountain warrior monks with red faces.
It is above all one of them, Sojobo, which has gained great importance within various traditions of Shinkage Ryu and Yoshin Ryu. Sojobo was the Tengu King of Mount Kurama. A style that has a very large origin both from mikkyo and the legend of Sojobo was Kyohachi Ryu, founded by Hogen Kiichi.
Tengu in the Middle Ages came to be mostly associated with the Yamabushi and their belief in Shugendo. As mountain warrior sect
(yama–bushi, mountain-warrior) they lived an ascetic life with extremely hard mental training.
Shugendo was a mixed religion based on Shinto, Taoism, esoteric Buddhism and local shamanism.
Kuji–kiri, ”the nine symbolic cuts”, is something that is intimately connected to mikkyo. These are the special hand gestures,
which remain in those koryu, which have in some way had some connection to ninja or yamabushi. Examples of schools are some
Shinkage Ryu and Katori Shinto Ryu.
According to belief, Kuji-kiri can activate the nine energy structures, the grids (power, energy, harmony, healing, intuition, awareness, dimension, creation and completeness).