I got the same emails and even messages on LinkedIn for years. They usually start with a sincere message, and then ask "do you know upwork?"

Last week was my first encounter with a Japanese developer.

I've been curious about the scam as well. My guess is that they're setting up accounts to pay you with stolen credit cards, and then you're going to wire that stolen money back to them (as it's clean now?)

But who knows. We need a Krebs on Security article.