This may be too late, as your post was a few months ago ... but perhaps it will help people who are looking to PCS to Japan in the future.
My husband and I are currently stationed at Yokosuka, Japan. We've been here since May 2008. And I have been working very closely with my doctors in Internal Medicine to find out about getting banded. We have a little less than a year until we PCS again, and I was told that if I have the surgery now, I will not be able to return to Japan for 3 years. So I have to wait until we PCS back to the States.
My doctor is the person who decides on the EFMP/overseas screening. So my source was THE most reliable. She's the ultimate decision-maker in allowing you to come over here or not. Apparently the Navy has a rule that you cannot go overseas within 3 years of having weight-loss surgery. She said that there might be an exception for a few places ... perhaps a 2 year wait for some places in Europe. But generally, it is a 3 year requirement.
Although Yokosuka is a relatively large base, they are not fully equipped for bariatric issues (along with several other needs). Some military facilities, like Balboa (San Diego) and Tripler (the Army hospital in Hawaii) specifically have bariatric departments that can handle our special needs -- including fills.
Regarding fills ... not just anybody can do the fills. Fills have to be done by someone who has trained in bariatrics and are familiar with the band and possible complications. As luck would have it, we recently had a doctor transfer from the East Coast and has been trained in bariatrics. However, she has never done them before. But her help would only come in handy if it's been more than 3 years since your surgery.
Hope this helps! And I'm sorry if it dashes any dreams, as Japan is an amazing place to live. But this knowledge will help you and your spouse be able choose appropriate orders.
Best of luck to everyone!
Kristen