It almost seems like it would be inevitable.
Research can and will hit a dead end.
Sadly, that's what I've been putting up with in the last few months. My work is a piece of fiction and set an a alternate reality Earth. However I still want to be as accurate as possible with anything that would be recognizable as genuine real world culture when I used the real thing and not any of the fictional culture I'm using for this thing. The biggest problem is that the culture I want to represent faithfully is one I've never experienced.
You can imagine how much of a pain in the ass this has become, and believe me, it very much is just that. However I'm keeping at it even as I continue my work as best I can while scouring through stuff online and in books in the hopes that I don't royally screw up and do something to offend my future readers.
Here's hoping the Japan Foundation can help.