In-boxes are filling up with an article from the Nikkei which says the Japan Post Bank has been intervening covertly in USD/JPY for the government, to keep safe-haven flows from overwhelming USD/JPY and EUR/JPY and pushing them lower (like EUR/CHF).

Usually we see flows from these guys at range-extremes to keep the dollar from falling but we rarely see them chasing the rate higher, so this is a new wrinkle. The market is taking it seriously, based on the price action, with USD/JPY near 92.50 and EUR/JPY trading at 123.25 despite Greece’s woes.

From the article:

The issue has drawn market attention due to widespread speculation that
the government is using the postal bank a tool for yen-selling,
dollar-buying market intervention. The bank's purchase of U.S.
government bonds is intended to prevent the yen from strengthening, some
market insiders said.

The accuracy of this view is unclear. But there is circumstantial
evidence to support it. A dealer at a Japanese bank, for instance, said
that the postal bank's dollar-buying prevented a further rise in the
value of the yen when it soared to the 84 level in November.