I would like to warn the reader in regards to a precise point: In English, it is usual to call a Buddhist school "sect." but this term has degenerated to take a on a pathological connotation referencing the new religious movements which, under cover of ancestral traditions, make money, deprive individuals of their freedom and are thus contrary to the Buddhist doctrines. In French the word "sect" sounds very bad, just as the word "doctrines" which seems synonymous with ‘wearing blinders’ or being willing deceived.
Shugendo is not a sect with the pejorative direction! It is an extremely old tradition whose practice requires : Fluency with the Japanese language, capacity to remain in Japan at the temple for a long time to study and practise, and the ability pass the tests necessary to be able to go more deeply into the study. Like the Knights of Europe in the search for the Grail, Shugendo is more a Spiritual Order that a religious movement even if its statute in Japan is that of a Buddhist school. Shugendō is much more than Buddhism. In addition, ancestral shugendō never tries to proselytize ! It does not seek to grow in a number, only to perpetuate a thousand-year-old tradition. This is the tradition of the Shogoin Temple, which is one of the oldest in Kyoto. Considerable new "sects" of Japan, with individuals dressed like Yamabushi, sow confusion in the mind of those who do not know and understand true Shugendō and who hasten to seize onto this bad image.
I had to study all the schools of Shugendō to know all the different doctrines which characterize them and I found in the Honzan-Shugen school of the Shogoin temple, to be the best for the western practitioners. Considerable numbers of ancestral Japanese schools of esoteric Buddhism (mikkyo) are not the paragons of virtue they are sometimes thought to be, in particular in Shingon or Zen. It is an absolute disaster for he who would try to follow this labyrinth of the new “sects”, the bad schools and the schools with mercantile goals. It took me twenty years to finally find this rare jewel that is a sincere and true school, with genuine traditions and individuals. But great thoughtfulness is required to become a member of it, not as simple as filling in a form. It is necessary to make strong efforts like learning Japanese and passing the examinations of entry and exit of the temple, of the Buddhist university. One can be expelled or put out (Hamon) if one creates faults which harm the community or respect for human dignity. To be a Yamabushi is not simple; it should be deserved! The Shugendo of the old temples Shogoin, Kimpusenji, Daigoji and Haguro Shozenin, is worthy of confidence, interest and does not have to be compared to an "unhealthy sect". I am saying this against such sects as "Shinnyo-čn, Agon-shu, Gédatsu-kai, Risho-kai" which sometimes use in their ceremonies the behaviour of Yamabushi! Mistrust and vigilance! I practiced more than ten years to be accepted by the Shogoin Temple! This is guide! If one says yes to you too quickly, be wary, perhaps it is the trap of a sect!