When we moved into our new apartment in March we noticed these signs all around the third floor landing in our stairwell.
They are the symbol of a Shinto shrine. I couldn't get them all into the picture, but they are every couple feet all around the bottom of the wall. I didn't know what to make of them but knowing that Japanese can be superstitious, Tomomi and I gathered that something bad must have happened on that landing.
Imagine our surprise when a few days ago the fourth floor landing (our floor!) looked like this:
I had to ask the apartment manager what it was all about. His answer was something I never would have suspected. Guess what he said. (Put your guess in the comments and in a few days I'll add the answer to this post.)
[Added 8/4] Thanks James, Tomomi and Brian for the guesses. Here's what the apartment manager told me. Some of the tenants in our building have dogs and occasionally let them pee in the stairwell (maybe when they are lazy or the weather is too bad for a walk?). The Shinto symbols are a prayer or a charm of protection from dog pee. They say it works. Hmmm . . . is it the prayer being answered or are the dog owners just less likely to let their dogs pee on a religious symbol than on a blank wall?