In the late 1970s, I was the branch manager of a US company here in Japan, and one of the banks we used was the Tokyo branch of a bank the home office used, the now-defunct Seafirst bank in Seattle.
We had no particular problems with them, and I distinctly remember them gifting me some tickets to watch Sumo tournaments in Tokyo. One day, however, it was brought home to me just how clueless an expat in Japan could be.
Most of the people running the bank were, of course, native Japanese speakers. My contact included one Japanese employee and an American, apparently from the Seattle headquarters. One day, when I was meeting with the American, whose name I do not recall, the Japanese fellow participated, using his English, which was quite good, this being necessary because the American was not a Japanese speaker.
When the Japanese fellow left the meeting room to get something, the American said to me, with a straight face “You know, these people use English among themselves, even when we foreigners are not around.”
I was toying with making a quip about the language of the sound a Japanese tree might make falling when nobody is around to hear it, but I refrained. Such an attempt of sarcasm might have cut me off from the Sumo tickets.