The bankruptcy of one of the world’s largest cryptocurrency exchanges, FTX has shown the world how vulnerable it is to invent in digital currency. Following the bankruptcy, the price of bitcoin (BTC) has fallen sharply. It is now about 2,295,284JPY, a sharp fall from over 8,000,000jpy year ago. Would you invent in such digital currency? Include benefits or drawbacks of introducing digital currency as the key currency in Japan as other countries are planning to do so.