Onbashira Festival 2022, 2028, 2034 every six years 御柱祭　おんばしらさい（Nagano Prefecture)

People Ride Big Trees Sliding Down the Mountainside

The Mihashira or Onbashira (Japanese: 御柱, honorific prefix 御 on-/mi- + 柱 hashira ‘pillar’) are four wooden posts or pillars that stand on the four corners of local shrines in the Lake Suwa area of Nagano Prefecture (historical Shinano Province), Japan. The largest and most famous set of onbashira are those that stand on the four shrines that make up the Suwa Grand Shrine complex.

Six Years Between Events

By custom, the onbashira are replaced every six (traditionally reckoned as seven) years, in the years of the Monkey and the Tiger in the Chinese zodiac. In Suwa Shrine, this occurs during the Onbashira Festival (御柱祭 Onbashira-sai), which also functions as a symbolic renewal of the shrine’s buildings. During the festival, sixteen specially-chosen fir trees are felled and then transported down a mountain, where they are then erected at the four corners of each shrine. Festival participants ride the onbashira as they are slid down the mountain, dragged to the shrine, and raised, and the festival has the reputation of being the most dangerous in Japan due to the number of people regularly injured or killed while riding the logs. This festival, which lasts several months, consists of two main segments, Yamadashi and Satobiki. Yamadashi traditionally takes place in April, and Satobiki takes place in May.