It’s interesting that you've made this research. I never thought about registering on a Japanese exchange. Now it seems as a promising opportunity to diversify risks and open a new market. At the moment, I stick to established exchanges like Coinbase, Binance, and CEX which have a great choice of coin pairs (including exotic ones, like BTG-EUR: https://cex.io/btg-eur). Maybe, you can provide some comparison of these exchanges with Zaif? I’d be very grateful.