I just found what seems to be the Japanese equivalent of VignetteBricks! The Art Museum of LEGO Vignette. It is in Japanese, but from my Babel Fish translation, it seems that there was an intitial thread on a Japanese-language message board (which seems to have a broken link), and various contributors built their own vignettes. Those creations, as well as more recent vignettes by AFOLs from Japan, are documented in this on-line museum. There are lots of great MOCs there (though I have to admit that I don't get some of them--I assume they're related to anime or other cultural references that I don't recognize). Here, for example, is one entitled Chim Chim Charee by Tera.
If someone knows more about this site, or if they know about the Japanese-language message board where these creations were first posted, I'd love to know more.