The Japanese (JASDF) were a customer for the tanker version of the Boeing 767 when Boeing was offering it in the early days. Japan and Italy were the only customers that I am aware of for that aircraft. Therefore, it was not a massive surprise that Japan ordered the KC-46 when Boeing developed it for the USAF. The first aircraft is now being completed and has been parked on the ramp up at Everett recently. Here it is undergoing some testing. Hopefully we shall get to see it flying soon.