Well, even if they did, it would be bad form to say anything about it - at least for now. In any case, I doubt we are seeing any official intervention as that would require coordination and sign off from US authorities as well. We're not at that stage yet. Here's a good graph depicting the history of currency intervention by Japan:
![Japan](https://images.forexlive.com/images/Japan_id_4d548747-a5cc-4f9f-8d23-5af9c7d134ab_size900.jpg)