"No money and you're dead" is essentially what yakuza characters in novels and comic books say, and they mean that literally.
Cash-strapped for over a decade after the asset price bubble burst in the early 1990s, the underworld is now seeing a rise in dirty money to help keep yakuza thriving, economists say.
"In the next five years, Japan's underground economy will expand at a rate of 2 percent to 3 percent; that's faster than the potential growth rate for the legal economy, which is about 1.5 percent," said Takashi Kadokura, a senior economist at Dai-ichi Life Research Institute and an author of several books on the underground economy.