In 2017, bitcoin was one of the greatest investment manias in recent memory. This year, that boom has turned to bust.

To understand what drives the wild cryptocurrency market—the technology, hype and innovation, combined with the hacking, market manipulation and increased regulation—we decided to experiment with a digital currency of our own: WSJCoin, a virtual token for the newspaper industry.

Traveling to Japan, a hotbed for cryptocurrencies, we found that creating a coin is relatively easy: Find a blockchain startup, watch the founder type some code on a screen and a cryptocurrency is born. No wonder there are more than 2,000 of them, according to CoinMarketCap.

What’s complicated is creating a cryptocurrency that is valuable, useful and has widespread appeal. So we began a journalistic venture to find someone who would accept WSJCoin for payment.

Along our way, we met quirky characters who epitomize Japan’s crypto craze: a popular all-female J-pop band called the “Virtual Currency Girls”; a 21-year-old student who spends most of his time mining cryptocurrencies; and a university professor creating a cryptocurrency for use exclusively on campus and in the neighboring college town.