Click the above link to see how much money the Japanese government owes in bonds. (Sorry, it's in Japanese only!)
The ironic part of it is that technically Japanese law does not allow for deficit spending. Unfortunately, that law has been ignored for a long time now. I'll try to get a link to that law if I can find it on-line.
The Mikawa Ossan's link does not take the financial asset of the public sector and/or private sector into account.
And it is lucky that the creditor of the horrible debt increasing by second is most sheepish Japanese, not other countries.
I don't know what would happen if a real nationalist claimed, "Strong Yen is a Japan's vital national interest, and let's change the US bond we have into Euro or Chinese Yuan".