A large Buddhist monastery MII-Dera temple is also known as Onze-JI temple. It was founded in the second half of the VII century at the foot of mount Hiei, near lake Biwa. During the heyday of the monastery there were about 850 of temples and other buildings. Currently it remains one of Japan's largest monasteries, within which there are more than 40 churches and other buildings. Historically MII-Dera temple is associated with another monastery located on mount Hiei, - Enryaku-JI temple, the monks of both monasteries were at war with each other or against another monastery. In addition, the monks of MII-Dera temple participated in the political games between clans for the throne.

Onze-JI temple was founded by Emperor Temmu in memory of the dead brother. Two centuries later, the temple got the name of MII-Dera (the temple of the three wells), descended from the mountain springs, which bathed newly born children. The name of the monastery monk gave Entin, former rector of MII-Dera temple in 859-891 years. In this period the monastery became one of the most influential churches in the country, along with Todai-JI, Kofuku-JI and Enryaku-JI. After the death Entin confrontation between MII-Dera temple and Enryaku-JI temple, which represented different branches (zimon and Sammon) of the Tendai school, escalated. In both monasteries were established its own army of monks, who regularly attacked each other, destroyed and set fire to the monastery churches and buildings. Only in the eleventh century MII-Dera temple as a result of such clashes was burned to the ground four times. Surprisingly, the two warring armies could unite and act together against someone. So, in the XI and XII centuries, monks from mount Hiei twice attacked the city of Nara and the temple of Kofuku-JI.

In addition, in the twelfth century the monks of MII-Dera temple twice and participated in the battles for the throne. And the first time they entered the war on the side of the Minamoto clan against the Taira clan, and the second was supported by the Taira clan vs clan Minamoto.

Until 1367 on mount Hiei continued peace and tranquility until one of the monks of MII-Dera temple was not killed at the entrance to the Kyoto monastery of Nanzen-JI temple. Army of the monastery moved to March to Nanzen-JI temple and, with the support of colleagues from Enryaku-JI temple and Kofuku-JI temple, twice defeated the army of the shogun who came to pacify them.

When in 1571 the ruler ODA Nobunaga destroyed the monastery of Enryaku-JI temple, MII-Dera temple also suffered, and most of the monastic army was destroyed. Some time later, the remaining monks were allowed again to build monasteries on mount Hiei.

Currently, the MII-Dera temple are kept for six statues of the Buddha and the treasure of the Japanese emperors, who show to the public once a year or on special occasions.