As Bob Cummings discovered, some Japanese social behavior is different than ours.

One morning in Beppu, I was walking up a hillside when I came upon a cave. Always curious, I looked in. It was a hot spring occupied by four elderly ladies enjoying the healthful benefits. Before I could retreat from this intrusion, all stood, smiled, bowed and said almost in unison "ohayogo zaimasu."

A good morning it was and an interesting experience for me. All of the gracious ladies were naked.