What Was the Furubochu?
Saigandenji Temple is said to have been founded in 726 by a monk from India named Saiei. Over time, the temple became a major center for volcano worship and for mountain asceticism. By the fourteenth or fifteenth century, several hundred yamabushi mountain ascetics had taken possession of the relatively flat stretch of land extending to the west of the temple and had developed it under the patronage of the powerful local Aso clan. This loose community of ascetics and monks became known as the Furubochu. Bochu means “an assemblage of monks,” while the prefix furu means “old.”
The land occupied by the Furubochu was subdivided into 92 plots, some as small as 100 square meters, some as large as 1,000. The hundreds of yamabushi who lived here erected 37 substantial wooden temples and 51 smaller, simpler thatch huts. They would spend their days practicing self-discipline via meditation, fasting, and sutra chanting; inspecting the pond inside the crater to get an idea of the mood of the deities; and guiding pilgrims to the highest permitted point for laypeople, who would worship the crater from afar.
Small stone pagodas were found here in the 1960s when a farmer bulldozed the area to make it easier to graze his cows. In the 2000s, Watanabe Kazunori, a professor of vulcanology at Kumamoto University, conducted some preliminary excavations. He discovered burnt pampas grass roof thatching from yamabushi huts, as well as wooden pillars from the temple buildings.