I have a few questions on IC cards, namely the NIMOCA IC card, mostly to determine how much money to add and how to buy.

I understand that the Nimoca card is the only card available at Fukuoka airport where we will arrive, and that you can purchase cards from the Bus Ticket window in the terminal? Do you need cash to purchase and then load the card, or can one use a foreign (US) Visa card?

I am traveling with my wife- should we get two NIMOCA cards, if we take the bus or train together, or can you swipe a card twice before entering trains or buses?

Later in the trip we will be in Okayama and Kyoto . Can you use the NIMOCA card on buses in both cities, and to pay for Taxi if needed? Can you use the NIMOCA card to pay for the train to go from Okayama to Uno (for Naoshima ferry), and can you use it to pay for the ferry from Uno to Naoshima?

Sorry for all the questions, but it is hard to find this INFO online.

Thanks

Each passenger must have one IC card, whichever IC card it may be. You need two in your case.

https://www.kkday.com/en-au/product/25163

JR Kyushu SUGOCA and Nishitetsu NIMOCA are available in the international terminal.

As long as JR West ICOCA is supported by transportation operators in Chugoku and Kinki, NIMOCA works.

You just tap the card on the reader, normally at boarding and alighting. Top up can be done by cash.

"Travel outside or between IC card areas

It is not possible to travel outside IC card areas. Both, the origin and destination stations have to be located inside the IC card's coverage area. Furthermore, it is not possible to use an IC card to travel between disjoined IC card areas (except when using shinkansen trains; see details below). For example, you cannot use it to travel between Tokyo and Sendai."

In order to use IC card train ride, a) both origin and destination stations must have reader device installed, and b) both stations must be in the same region. a) is obvious. b) is by turnaround time. By limiting the region, fare calculation turnaround time is guaranteed. Combination is exponentially augmented for multi region computation.