Allocation J Currencies

I am trying to understand the values for Allocation J Currency fields in order to calculate the Net Amounts. In the below example the New Single Order values are being used to create the J Message.
The New Single Order Currency Field is JPY
The AllocAcct Currency equals USD
In the above case all AllocAcct calculations are provided in JPY and SettleCurr and SettleCurrAmt is in USD?