It could be argued as worse because the debt soft default though repaying nominal value while losing real value is borne by the Japanese citizens. USA will see the whole world lose value for holding its debt, its partly why nobody wants to break ranks with the reserve currency because its obviously going to fall apart and lose alot of money, reset the economies they interact with. When elected most choose to grin and bare the slow failure of sovereign default. From what I can see the thread unwinding so that nothing holds and is inevitable in Japan or anywhere else just because economics is a study of natural phenomena not the ability gained to manipulate endlessly, ie. humans are fallible and economies are elemental.
Anyhow the Yen and Japanese government are broke yes but Japan itself has a net trade balance but also declining demographic growth nationally. The economy can be fixed over about 30 years but the debt will default and the currency will reset like the Rouble is equal to 10,000 of old Roubles which is default in all but name. Soft default is when bankruptcy is not declared but no correct value is returned, so government pensions pay out but the age to claim is raised beyond life expectancy after a life time of contributions are made. If we took a list of governments which have soft defaulted on pension plans and so chopped trillions off their obligations and debt without admitting failure, its probably more then a dozen including many of the worlds richest countries.