Japan’s government is able to pay such a low rate of interest because domestic prices have been falling for more than a decade, while the yen has been strengthening against other major currencies. Domestic deflation means that the real interest rate on Japanese bonds is higher than the nominal rate.
日本政府之所以能够获得如此低的利率，是因为十多年来国内物价一直在下降，而日元则对其他主要货币升值。国内通缩意味着日本债券的真实利率高于名义利率。日元升值则提高了日本债券相对于其他货币债券的收益率。