Cash is still king in Japan, and that means the central bank doesn't see a need to mint a digital currency for now, according to the head of the FinTech Center at the Bank of Japan.

"We aren't at the stage of considering issuing a digital currency because there is no demand," said Yuko Kawai, the head of the BOJ division, in an interview last week. "To begin with, do we really need a digital currency in the nation where cashless living isn't making much progress?"

Kawai speaks from experience — since taking over the job about a year ago, she's tried to stop using cash in her personal life. But while life is "much easier" without needing an ATM so often, there are many things that still require physical money. If you want to split the cost of dinner with friends, or pay for a taxi in rural Japan, she said, you need cash.