What is it?
THE MONKS WHO MUMMIFIED THEMSELVES
As surprising as it sounds, Japan, too, has its own mummies. There are 17 mummies in Japan, within which 7 belong to Mt. Yudono's practice of Shingon Buddhism (esoteric Buddhism).
4 of them can be found in Tsuruoka City.
Monks believed mummifying their own bodies would make them experience the most atrocious pain in life, allowing them to become Buddhas so they could protect the people around them. The practice was forbidden by law in 1877.
"Becoming a Buddha to save the Poor and the Sick"
There are 11 mummies within 150km around Mt. Yudono, out of the 17 mummies present in Japan. Why are there so many Sokushinbutsu around Mt. Yudono?
Shingon Buddhism temples long directed mt. Yudono. Shingon Buddhism is different from other Buddhist schools in that it teaches its disciples to reach a Buddha-like state during their present life (and not after death). The poverty and the illnesses striking Asahi village during Edo Period made the monks even more dedicated to their tasks of becoming Buddhas, the only being that is able to deliver the Humans from their suffering. An extreme practice of Shingon Buddhism's teaching was born: the sokushinbutsu auto-mummification training.
How to become a Sokushinbutsu
1) Enter a monastery (a lot of the mummified monks entered a monastery out of guilt after committing a crime)
2) Be an exemplary monk for many years
3) When you feel like it's time to go, announce your wish to your disciples.
4) Make a pilgrimage all around Japan to collect alms. Come back.
5) Retreat in the mountain for your last 2000-4000 days.
6) During your retreat, stop eating the 5 holy grains (rice, millet, soybeans, azuki beans, and wheat) to lower your body fat. Fat is what makes bodies rot.
7) Push your diet further and stop eating all kinds of grains.
8) Push it a little further to eat only tree bark, roots, and leaves.
9) When you feel your end is near, dig a pit 3 meters underground. Protect the hole from humidity by stacking stones in the "walls."
10) Before sealing the place, place two bamboo pipes from the surface so your disciples can give you water and so you can breathe. Bring with you your urushi-lacquer tea and a little bell.
11) Seal the pit. Drink your poisonous urushi tea to disinfect your organs from the inside. Ring the bell when you're thirsty.
12) Your end has come. You have to wait 1000 more days before your disciples excavate your body (1000 days after the last bell ring). If your body hasn't rotten, congratulations, you have succeeded in becoming a Sokushinbutsu! Otherwise... Well, at least you tried!
Disclaimer: This text is written in the second person for entertainment purposes.
DO NOT attempt this at home.