Cleanliness is next to holiness and instruction placards are not far behind.

Interestingly, most places don't have towels of any kind, and usually not a blow-dryer either.  People carry their own little towels with them.  I frequently observe women drying their hands with their hair, styling as they go.  Think of the trees that could be saved if other countries adopted this practice!  (Not the hair thing, necessarily.)  There is a large market for stylish little drying cloths, some quite expensive.  I imagine there are status statements being made in the public restrooms of Japan.