Buddhism has played a huge role in the cultural history of Japan and still does today. Buddhist ceremonies are well attended by people of all generations and are celebrated all year. There are many different forms of Buddhism, from the traditionally Japanese Zen Buddhism to more elite sects such as Shingon Buddhism practised mainly in Yamagata in the North of Japan.
Buddhism first came to Japan via China after China was introduced to Buddhism from India in 67 AD. Buddhism then traveled from China into Japan in 467. This endeavor was facilitated by five monks from Gandhara who travelled to the most eastern land to introduce Buddhism. The official date of the introduction of Buddhism is actually stated as the year 552 when monks or nuns came to Nara with an image of Buddha. Empress Suiko is often praised as the one to begin the spread of Buddhism when she openly encouraged the acceptance of this new practice. Through travel between China and Japan, Buddhism became more popular and by the year 627 there were 46 Buddhist temples across Japan. Buddhism grew across the centuries in Japan, with the warrior class famously adopting Buddhism. The Meiji restoration brought about a very anti-Buddhism sentiment and a movement to eradicate Buddhism from Japan began. The separation of Shinto and Buddhism began with the destruction of many Buddhist aspects of temples across the country. Today Buddhism still holds influence in Japan, with 90% of funerals conducted centered around Buddhist rituals.
In Northern Japan in the area of Yamagata specific school of Buddhism; Vajrayana developed the process and practice of self-mummification. We usually associate mummification with Egyptian practices, however this sect of Buddhism also adopted this as a form of enlightenment. This practice was mainly used from the 11th century until the 19th century, and is actually illegal in Japan today. This practice is based on the idea that all living things carry within them the potential to attain Buddhahood. This is said to have started in this particular sect after one monk buried himself alive in order to end a famine. When they dug him up three years later they found the monk had become mummified, so the others in the sect aimed to continue this practice.
The process of self-mummification was developed over the years while being perfected by monks. There are four main steps to achieve this process. The first is that for three years your entire diet will consist only of nuts and berries, and exercise has to be taken daily. For the next three years only eat bark and the roots of plants, and continue to exercise. Once you have removed a lot of your body fat and moisture through this six years of dieting you are to drink a special tea. This tea is produced from the urushi tree, usually used to lacquer bowls. This made the body inedible to maggots and also dried out the body. Now you are very thin and dry you can seal yourself into a stone tomb. The monk would thread a bamboo pipe for air so they could breathe in the tomb and also a bell to signal that they are still alive. The monk would sit in the tomb, in lotus position, until he died. Once this would happen to the tomb would be sealed to allow the monk to mummify for 1,000 days. Unfortunately, this technique was not very effective. For those that did achieve mummification they were considered Buddha and enshrined in the temple for viewing. To this day 24 monks have been found in this mummified state.
Today if you visit the Yamagata area of Japan you can go to the temples in which these mummies are kept to see this sight for yourself.