Furthermore, Bitcoin doesn't really offer much new to the trade culture in Japan. As a society, they tend to be very cash & local trade biased, and even online shopping isn't (demographicly) as big in Japan as it is in the (much more geographicly diverse) United States. Sure, they use the Internet to decide what to get, but oftentimes they can order the item online and pick it up at a store within a local travel distance for cash. Walmart.com uses a similar model. Even when they do trade electronicly, they actually have more advanced forms of electronic commerce than is presently available in the US or Europe, already having NFC enabled smartphones and such. In the US, the credit card industry has been secretly resisting moving away from the plastic card model and towards the smartphone app model because they have a huge vested interest in the prior model, while companies like Google have a head start in the latter model.
Add to this the commonality of both the names "Satoshi" and "Nakamoto". Especially Satoshi. Basically, bitcoin was invented by John Smith.