In the ancient forest with towering cedars, all was silent except for the invisible sound of birds chirping.
Suddenly I heard the sound of the bells. From behind the fog, a dozen figures appeared, walking in a line.
Led by the figure of a Tolkienian man with a long gray beard, they looked like ghosts, dressed all in white.
They are the Yamabushi: Japanese mountain worshipers.
For more than 1,400 years, centuries ago before anyone spoke of "forest bathing", Yamabushi monks had walked the sacred mountains of Dewa Sanzan (translated as, "Three Mountains of Dewa province") in Yamagata Prefecture.
But their journey was not a very pleasant hike. Through union with nature and strict self-discipline, Yamabushi seeks spiritual rebirth.
Yamagata is located in Tohoku, the northernmost region of the Japanese island of Honshu.
Most of Tohoku is isolated, full of mountain ranges, and prone to the heaviest snowfall in Japan.
This is the land described by haiku poet Matsuo Basho in his book Narrow Road to the Deep North (1689).
The sacred or sacred status of these three mountains - Mount Haguro, Mount Gassan and Mount Yudono - dates back to AD 593 when Prince Hachiko fled the Japanese capital, Kyoto after the assassination of his father, Emperor Sushun.
Prince Shotoku, the Emperor's nephew, advised Hachiko to flee to Mount Haguro, where it was said that he would meet Kannon, the Goddess of Mercy.
Prince Hachiko built a shrine on each of the three peaks so that the mountain gods would remain there, thus ensuring the peace and prosperity of the region.
As it developed, Shugendo incorporated elements of Shinto, Buddhism and Taoism.
Shugendo is a Yamabushi religion. "Historically, Yamabushi lived in the higher mountains of Japan.
"They spent years in the mountains," explained the Bunting Team, the Yamabushido Project Leader and Assistant Yamabushi Experts.
"For example, a Yamabushi who undertakes austerities to become a Sokushinbutsu (Living Buddha) must spend at least 1,000 days in the mountains."
The process of self-mummification involves long periods of heavy fasting, and the practice was banned more than 100 years ago during the Meiji era (1868-1912).
Currently, there are about 6,000 Yamabushi in Japan. They believed that training the Shugendo hermit in a harsh mountainous natural environment could bring enlightenment.