I don’t know how they go about setting the mid-point or how they can justify setting the Yuan so weak when USD/JPY is on 15 year lows. CNY/JPY is at really important levels, currently trading below 11-year lows around 12.20. This does not speak of cooperation on currency issues heading into the G20 meetings.
The argument will be that they are trying to ward off hot money from flowing into China but that can only explain so much. I’m sure that Japanese authorities are throwing their hands in the air in frustration.