Young men prove their bravery by riding giant logs down steep hills in bizarre Japanese Ki-otoshi ceremony
Bravery isn't the first word that comes to mind when looking at these images of a Japanese log-rolling ceremony.
But that is exactly what these young men are apparently proving during the bizarre Ki-otoshi ceremony, where they ride the giant logs as they are yanked down steep hills by ropes.
Skidding and bumping over the rough terrain, at times the logs literally drop down the steep inclines.
Someone always gets hurt. I fell off and broke a rib on my first time down,' said Kazuaki Miyasaka, a spry 60-year-old former sushi chef, after taking part in the ceremony in 2004.
The practice forms part of the Yamadishi segment of a Japanese festival called Onbashiri, the 'sacred pillar' festival.
Onbashiri is ancient - it has been celebrated in the Lake Suwa area of Nagano for 1,200 years.
The festival takes place every six years and consists of two segments - Yamadishi, which takes place in April, and Satobiki in May.
Before Yamadishi, which means 'coming out of the mountains', the huge trees are cut down with axes made especially for the job.
They are decorated in the traditional colours of Shinto ceremonies, red and white. Then the ropes are attached, and teams of men drag the logs down the hills towards the four shrines of Suwa Taisha.
In the Satobiki part of the festival, the logs are specially placed to support the foundations of the shrine.
Sixteen logs are used, four for each shrine, in an effort to renew the power of the shrines.
Men sit on the logs as they are raised and sing to mark the occasion.
Onbashiri was demonstrated during the opening ceremonies of the Nagano Olympics in 1998.