Ed, at GEEKED.INFO has written an enlightening article on sokushinbutsu:
How to mummify yourself in 4 easy steps
1. Change your diet
For 1000 days (almost 3 years), only eat nuts and seeds that are naturally found. This, in combination with hard physical training will reduce your body fat to nearly nil, eliminating an easily decomposable part of your body.
2. Switch to Bark
Ok, now that you are sick of eating nuts and seeds for almost 3 years, it’s time to switch it up. For the next 1000 days, eat only the bark and roots from pine trees. This will reduce the amount of fluid you have in your body, leaving you even more dessicated.
3. Start drinking poisonous tea
Towards the end of your 1000 day stint eating delicious bark and roots, start drinking tea made from the sap of the urushi tree. Usually this sap is used to make laquer, but it will help you vomit, sweat, and urinate more often. This will help get rid of that terrible moisture in your body. Oh, and it will help to kill any maggots or other insects that might try to eat your mummified body later.
4. Lock yourself in a tomb
Finally, you’ll want to enclose yourself in a tiny tomb, just big enough to sit lotus style in. You’ll hang out in here for the next 1000 days, but chances are you’ll die long before you hit the 1000 day mark. How will you breath? A small tube will be run into the tomb. How will everyone know when you’re dead? A bell will be placed inside. Ring this bell every day until you die, then stop ringing it. When we don’t hear the bell anymore, we’ll pull out the air tube and seal up the tomb.
When the last 1000 days are up, we’ll crack open the tomb to see if you were successful. If we find a mummy, hurray! You’ll be considered a Buddha and will join an elite group of only a couple dozen monks who have succeeded over the years! If you’re all rotted, we’ll commend you for your effort, and tell you better luck next time. Want some tips? Try drinking the water from the sacred spring on Yudono mountain in Yamagata. I hear it helps because it has arsenic in it to help kill off any bacteria or micro-organisms. Oh, and watch out for the government, this whole practice was outlawed by the government back in the late 19th century.
Mt. Yunodo in Yamagata is a center for sokushinbutsu (self-mummified monks). You can go and actually see the corpses of monks who attained Buddha-hood while living (or through death, really) in several temples. The following temples allow tourists.
Two mummies; Chukai (mummified in 1755) and Enmyokai (1822) reside here. The temple is conveniently located on a hill in Sakata City.
Hours: 9-17:00 (Apr-Nov) or 9-16:00 (Dec-Mar)
Admission: 400 yen for adults
Access: 5 mins on foot from Kotobuki-cho bus stop that is 5 mins by bus from JR Sakata Station.
The temple houses Tetsumonkai (1829), an intense figure to say the least. It is said that he removed his own left eyeball as part of a ritual to ward against the eye disease that was pandemic at that time. He also allegedly castrated himself and handed over his manhood to a prostitute who was trying to seduce him. Dainichibo temple is nearby.
Hours: 8-17:00 (May-Oct), 9-16:00 (Nov-Apr)
Admission: 500 yen for adults
Access: 20 mins walk from Oami stop on the bus line bound for Mt. Yudono from JR Tsuruoka Station.
The mummy of Shinnyokai (1783) is kept here. Though a bit commercialized, the mummy is well kept with 6 yearly wardrobe changes. Dainichibo is the main temple on Mt. Yudono and is located near Churenji Temple.
Admission: 500 yen for adults
Access: 15 mins walk from Oami stop on the bus line bound for Mt. Yudono from JR Tsuruoka Station.
Their English website is here.
Nangakuji Temple houses Tetsuryukai’s mummy. He was mummified at the age of 44. The mummy supposedly survived a serious fire in the Showa era that burned down the entire temple complex.
Admission: 300 yen for adults
Access: 4 mins walk from Nangakuji stop on the bus line bound for Atsumi Onsen from JR Tsuruoka Station.