thinfor

Yes, I think it's Manchurian yellow wagtail (東北黃鶺鴒) Macronyx subspecies.  See whether any experienced birders would confirm this.

thinfor

Thanks John for your confirmation and Grace for the photo.

This, again, shows that every single common bird has to be WATCHED.  That makes us understand more about the common species as well as may bring us some surprise.