The rapid slump in the yen on Thursday should bring along verbal intervention from Japanese authorities today.
I'm only expecting verbal intervention, not actual yen buying, but this can be enough to scare yen shorts into covering (i.e. buying back some their yen shorts and sending JPY crosses a little lower).
Comments are likely from Japan's finance minister Suzuki, and we had some from the economy minister also earlier this week
The most impactful comments come from Japan's Finance Ministry's Vice Finance Minister for International Affairs Kanda. He is the guy (its normally a guy, yeah) who will instruct the BOJ to intervene, when he judges it necessary. Often referred to as Japan's 'top currency diplomat'.
As for actual yen buying intervention, it'll be preceded by more pointed comments. I have a guide here:
Japan's Finance Ministry's Vice Finance Minister for International Affairs Kanda