When I first went to Japan (1989) one of the people I worked with had studied in a temple and I ocasionaly noticed her walking up and down the stairs, 'carefully,' and sometimes, backwards. I never 'mentioned' it.
Back to the present - I was recently on a business trip in Japan and, as usual, took my keikogi and visited whatever dojo I could find. Well, I went to Hombu for the first time in ages and while training noticed some guy walking down the stairs, backwards, twice, which seemed odder as I didn't notice him going back up. So, my question is, why?