As Japan bets on a big economic boost from the 2020 Olympics, it might be dismayed by what's happening right now in Russia. Moody's doubts the Sochi Games will be much of a plus for that economy.

Yet there is one sector of Japan's economy sure to profit handsomely from Tokyo 2020: mobsters. Tokyo won't spend anywhere near the $50 billion Vladimir Putin did turning a Black Sea town into a global tourist destination. More likely, preparations will involve around $5 billion of construction projects over the next six years. And where there are cement trucks, there are gangsters.

What worries yakuza expert Jake Adelstein isn't the cash that organized-crime groups will be extorting below the radar screen. That's a given in a nation in which gangsters operate legally, pass out business cards and enjoy lucrative relationships with government officials.