Don't forget that Sachiko has the 'inside running' here - she's part Japanese and lived there for some time. Plus we did extensive research before she got her's, including the option of getting them done by Japanese surgeons - she decided that their work was actually TOO natural looking for what she wanted!
Once you've really researched this topic from the point of view of getting them, you start to see the signs where you wouldn't have before - once again, I'm guessing that the majority of the bikini girls are implanted, although Miki Sawaguchi definitely isn't and Anna Ohura probably isn't.
As for the teeth thing, oddly Japanese (and Asians in general) really don't seem to care very much about this!
Fake boobs certainly do not run contrary to Japanese culture - this sounds like a made-up factoid to me. Indeed, fake boobs are actually quite popular there!
Lee
P.S. Everyone who feels Sachiko's tits are absolutely convinced they are real, and if you watch the "Breast Care" videos on her site you'd probably think so too!