Japan's FX chief, Mimura, has expressed concern over yen movements. According to reports, Mimura stated that he is on alert and not reassured by current developments.

Further details on Mimura's comments and the situation with the yen are available from the source. The FX chief's statement indicates a sense of caution and vigilance regarding the yen's movements.

The source provides more information on Mimura's remarks, which can be consulted for a more detailed understanding of the situation and the FX chief's stance on the yen.