Bank of Japan Governor Kuroda issued soothing comments in his statement earlier:

It was a very brief statement, no TL;DR at all.

MNI over the weekend were expecting something:

The Bank of Japan duly announced they were buying 500bn yen in JGB repurchase future delivery (an add of liquidity)

Whatever it is, its doing the trick. Equity futures coming back up in the US also (ES on Globex is higher on the session)

Nikkei:

Bank of Japan Governor Kuroda issued soothing comments in his statement earlier:

The loses for AUD and NZD reversed hours ago, pre-empting all these other markets finally catching up.

Why yes, I am biased - FX rocks!