I used a Lawson's ATM in Aomori and am certain that it showed me the cost in yen. Otherwise, I would not have done the transaction in USD.

I used a checking account debit card with a Visa logo. There is no fee from my bank and they rebate the fee charged by the bank that owns the ATM.

It posted to my account on Nov 7 as:
Cash advance ATM -$202.57 (this is for 30,000 yen cash plus 220 yen fee)
ATM fee rebate +$1.47 (the 220 yen)

The rates for those two transactions would be:
30,220 / 202.57 =149.18
220 / 1.47 = 149.66

I definitely did the withdrawal on the 6th or 5th in Japan. That would have been the 5th in USA or wee hours of the 6th. The interbank rates were:
149.99 on the 6th
149.47 on the 5th