In an interview with NHK Broadcaster on Monday, Atsushi Mimura, Japan’s newly appointed Vice Finance Minister For International Affairs and top foreign exchange official, said that “authorities are always watching markets.”

Additional quotes

Yen carry trades built up in the past are likely to have been mostly unwound ...but if such moves increase again, that could heighten market volatility.

We are always watching markets to ensure that does not happen.

Authorities stand ready to act if currency moves become extremely volatile and deviate from fundamentals in a way that cause problems to firms and households.