While discussions of what goes on in the bathroom may make most Americans uncomfortable, it certainly isn't so taboo as to point out a different toilet. Perhaps the Japanese culture is different, such that, while people may have wanted to ask why you have a fringe toilet, social norms kept them from doing so.
I'm not Japanese, nor have I spent any time in Japan, so that's purely conjecture, but, knowing what little I know about Japanese culture, that wouldn't strike me as beyond belief.
I'm not Japanese, nor have I spent any time in Japan, so that's purely conjecture, but, knowing what little I know about Japanese culture, that wouldn't strike me as beyond belief.