Tour guides in Japan with Japanese clients do not get tips. I know that because my family friends work for tour industry in Japan and I had few tours in Japan with tour guides, by Japanese tour company not by non-Japanese company.

I do not agree with non-Japanese company try to enforce non-Japanese customs when doing business in Japan. Does not matter what International Tour Directors of America says, don't enforce the U.S. customs in Japan. Some elderly in Japan consider tipping by a customer insulting.