When I pay in Euro for 7 days in Osaka, Airbnb charge me 391.99 at the hostel/ apartment I choose to book with, for myself and my girlfriend.
The host obviously wants to receive Japanese Yen as their payment so the host sets their price in Yen and then airbnb could receive any currency from you, and pay the host in Yen. Obviously Airbnb smack a 4.24% fee for this convenience of me paying in Euro instead of Yen.
When I click to change currency in the bottom right hand corner to Yen I get a different price.
The price in Yen was 48774 in total, per google ( market interest rates at the time) this cost is actually 376.01.
If I was to pay the 48774 with my normal bank card in Yen the bank will charge me an exchange rate and a fee to pay in yen. Probably close to what the airbnb difference is. ( 391.99- 376.01 =15.98).
google search at the time ... obviously changes with time ,
However what I actually did was topped up my revolut mastercard with euro from my bank account ( no fees to do this).
Converted the euro to yen at the market interest rate - revolut charges no fee for this during the week when markets are open. At night or on weekend there is 0.5% fee.
So in essence Revolut app saved me 15.98 euro, which is useful.
I am grateful to have my revolut card, I'm not getting paid to say how great they are, it just could save you a few bob, link below or get the app on google play and probably the apple iphone store.