In North Japan, by the Yamagata Prefecture, are almost 2 dozen mummified Japanese monks called Sokushinbutsu. They are unique, each caused their own death and mummified themselves. The act of mummification would take around ten years to complete. It is believed that hundreds of monks have tried to mummify themselves, but less than two dozen actually succeeded.
The first step was a special diet of strictly nuts and seeds, along with heavy exercise. This left them with very little to no body fat, and this step took around 3 years. For the next 3 years, the monk would eat only bark and roots; he also added a poisonous tea made from the sap of the Urushi tree to his diet. The tea induced vomiting and a rapid loss of bodily fluids, but it’s believed that the main reason they used it, maggots would not feed on the corpse after this tea was ingested.
At last, the monk would lock himself in a stone tomb just large enough to fit his body. With nothing but an air tube and a bell, the monk would set himself in the lotus position; he would ring the bell daily to let others know he was still alive. When the daily bell ceased to ring, the tomb would be sealed; for 3 years, the tomb would not be bothered. If the monk had been successful and the body was mummified, the monk would be seen as Buddha and his body would be moved to the temple to be viewed by all. As impressive as this is, the act of self mummification is actually banned in Japan today.