It seems impossible that someone could mummify themselves. But that's exactly what sokushinbutsu is. This self-mummification was a religious practice undergone by Buddhist monks in 11th to 19th century Japan. While the extreme process may seem brutal, the monks who attempted it viewed it as a way to achieve further enlightenment.
That doesn't mean self-mummification is easy. Monks deprived themselves of food and eventually entombed themselves while they were still breathing, all in pursuit of a higher state of being. Successful sokushinbutsu monks are considered living Buddhas.
Sokushinbutsu has been banned in Japan, but some of these Japanese mummy monks still survive today. The Dainichi temple mummies on display give an eerie window into this sacred ritual, with their carefully preserved bones and colorful robes. The monks' remains stand as the ultimate reflection of a life of self-denial.
The process of self-mummification typically requires 3,000 days of ritualistic training. This preparation period is necessary for a monk to transform his body into a lasting relic.
The most important physical aspect of this process focuses on diet. Japanese monks attempting to achieve self-mummification would first stop consuming grains and cereals. For the first thousand days, they would only eat nuts and berries.
In the next thousand days, monks would solely consume things like pine needles, tree bark, and resin. This is why the sokushinbutsu diet was called “tree-eating,” or mokujikyo. If that wasn't intense enough, some x-rays of sokushinbutsu mummies have even revealed river stones within the stomachs of mummies.
After two thousand days of strict dieting, the monks' bodies begin to waste away, undergoing extreme starvation and dehydration.
The extended period of starvation fulfilled the "necessary requirement of suffering," and also solidified the basis of mummification. As the monk starved, his body rid itself of fat and water - both materials that encourage decay after death.
In short, starvation made the monk's body resistant to bacteria and insects.
While undergoing starvation, it was common for monks to ingest toxic nuts and herbs to inhibit the growth of bacteria in their bodies. A popular drink was tea made from the bark of the Urushi tree, also known as the Japanese Varnish Tree. The sap from this tree contains abrasive chemicals that can cause a rash much like poison ivy.
Drinking this tea hastened the monk's death while helping to preserve his body from the inside out.