OK there's a reciprocal agreement between Japan and Australia but the 'X' after the 9 is not correct, thus VK9X/JO1AEC is not correct, VK9/JO1AEC is. I was looking into either operating from Christmas Island or Cocos Keeling myself a few months ago, being a CEPT HAREC Class A license holder I wasn't certain on the matter of having to add an 'X' or a 'C' after the VK9 prefix so I contacted the regulating body in Australia. Glenn Dunstan, Advisor on the matter at the new regulating body AMC www.amc.edu.au/industry/amateur-radio wrote me that the prefix is to be VK9/ followed by your call. So no C, X, W, L or N after the VK9. If our Japanese friend only had checked with the authorities..