[Nyororin]

I am going to give my personal opinion on this...

Stick to places you know, or places that don`t exist but are still within your culture and experience... Otherwise leap to total fantasy. Anything that falls between those two (places that exist but are filled in with lots of fantasy) is really going to fall flat for anyone that doesn`t share your exact background. Especially for people who do know the location and culture you`re writing about, and who can tell at a glance how much fantasy there is.

You just don`t have the background to write a believable Japanese character. And please don`t take that as an insult - it`s pretty common. I couldn`t write a believable (insert pretty much any nationality other than Japanese or American - and even American is getting kind of doubtful these days) character no matter how hard I tried. Even if you do tons and tons of research, get the setting down to photo-realistic levels, you still have the problem of how the characters would act and react to various things. No matter what their personality, people are so heavily influenced by their culture and lifestyle that without having some sort of experience in the same culture and lifestyle... It is pretty close to impossible to write a good believable character.

I avoid at all costs books and movies of this type. I have read some truly horrible published books taking place in "Japan" with "Japanese" characters. It is almost always in name only, as they do things no Japanese person would do, say things no Japanese person would say, and live in a place that certainly isn`t Japan. In the end it is cringe worthy and completely ruins a book no matter how great the writing or story is.

One of the best pieces of advice for writing is to "stick to what you know".
And if you don`t do that, "stick to things that no one knows".