No matter where you go, you aren't going to get interest rates as you would in the States; not even close as they've always been next to 0%. So, keep savings out of the equation—you just need an account to receive currency.
You would just have to at this point determine what your short-term and long-term goals are in Japan.
If your short-term goals are to reside in Okinawa, I would highly suggest JA Bank. I believe if you get car insurance with them as well, they offer a slight discount (tip: if your significant other has a Japanese license and it's a gold bar, show them that for a larger discount and not your green/blue bar). The big plus about JA is that they seem to be more rural so you don't need to hunt them down as much as you would the bigger banks closer to the city center.
Another option is OkiGin(kou), or, The Bank of Okinawa, written as 沖縄銀行
(kanji) and mostly identified on ATMs and some buildings as おきぎん
(hiragana). This is because they are larger and can be found in more areas than JA. Though, I'm unsure about what other services they offer above just banking, besides having a business loan center.
If you ever see yourself moving from Okinawa around to other prefectures or even staying, JP Bank would be a good option as well. This is because it makes it convenient to not only get your withdraws but to ship packages off at the post office as well (JP Post) as they're typically 1-stop locations.
I personally only have JA as I've been with them so long to get a car insurance deduction with good standing.
If I were in your situation, I'd look at what is offered the closest to you as traffic can be a nightmare and open an account there if you just need quick withdraws and deposits and nothing more (note: some banks allow withdraws at convenience stores but sometimes charge as high as 200 yen per transaction). Afterward, decide on what you are going to do in Japan and what you can consolidate in one place, such as car insurance, life insurance, etc., to make banking and bill payment less of a burden.