JPYC (JPYCoin) is the first Japanese-yen stable coin that takes advantage of blockchain technology (ERC20). It is operated in the main net of Ethereum and always available in the transaction for 1 JPYC as 1 yen. We can use it as a Yen-denominated coin in our wallet such as Metamask and secondary markets such as Uniswap. JPYC, a Japanese stable coin, provides payment methods in transactions in cryptocurrency markets where the large price fluctuations block our way to buy and sell goods. It also gives us some choices to deal with the risk of user’s exchange fluctuations in cryptocurrency.