Some Japanese startup friends of mine are now living in  San Francisco and competing in the toughest startup ecosystem in the world, and they’re doing just fine. The team put together a great pair of resources. One for entrepreneurs and startups wanting to explore the Japanese market, and another site for Japanese founders who want to go global — or at least go Silicon Valley.
Great tools and a useful resources from guys who actually walk the walk.
Japan Entry 101:  http://www.jpentry101.com/
SF Startup 101:   http://startup.wiki.fc2.com/