With strong regs in Japan still stopping the main roll out of Crypto, the introduction of a 'J-coin" seems very strange, especially when despite the name is not actually a crypto coin.
It has been introduced with the unusual name as a competitor to Wepay and the like.
With 60 banks supporting it may do OK, although Wepay are so big it is hard to see the point of difference that j-coin offers.
Or perhaps this 'coin' is a precursor to a real J-coin, get the name out there, and we will build the coin blockchain later
Time will tell
https://beincrypto.com/japanese-banks-launch-digital-currency-without-a-blockchain/