Self Mummification

For a little less than three years the priests would eat a special diet consisting only of nuts and seeds, while taking part in a regimen of rigorous physical activity that stripped them of their body fat. They then ate only bark and roots of pine trees for another three years and began drinking a poisonous tea made from the sap of the Urushi tree. This caused vomiting and a rapid loss of bodily fluids, and most importantly, it made the body too poisonous to be eaten by maggots. Finally, a self-mummifying monk would lock himself in a stone tomb barely larger than his body, where he would not move from the lotus position. His only connection to the outside world was an air tube and a bell. Each day he rang a bell to let those outside know that he was still alive.
When the bell stopped ringing, the tube was removed and the tomb sealed. After the tomb was sealed, the other monks in the temple would wait another three years, and open the tomb to see if the mummification was successful.
If the monk had been successfully mummified, they were immediately seen as a Buddha and put in the temple for viewing. Usually, though, there was just a decomposed body. Although they were not viewed as a true Buddha if they were not mummified, they were still admired and revered for their dedication and spirit.
 It is believed that many hundreds of monks tried, but only between 16 and 24 such mummifications have been discovered to date.
 Video of a shrine to a self-mummified priest:
http://www.youtube.com/watch?v=usaWz4KwG6w&feature=player_embedded


Sources:
Yoldas, Ilker.The Self-Mummified Monks of Japan. July 1, 2007. Visited Nov 29, 2010. http://www.thethinkingblog.com/2007/07/self-mummified-monks-of-japan.html

Hori, Ichiro.  Self-Mummified Buddhas in Japan. An Aspect of the Shugen-Dô ("Mountain Asceticism") Sect . History of Religions. Vol. 1, No. 2 (Winter, 1962), pp. 222-242. Published by: The University of Chicago Press. Stable URL: http://www.jstor.org/stable/1062053

Sharf, Robert H.  The Idolization of Enlightenment: On the Mummification of Ch'an Masters in Medieval China . History of Religions. Vol. 32, No. 1 (Aug., 1992), pp. 1-31. Published by: The University of Chicago Press. Stable URL: http://www.jstor.org/stable/1062719