Dear Sheng,
Thank you for contacting Google. The phone needs to be in country of purchase, when the phone is in Japan and ready for shipping just e-mail me with 'I CONSENT' to the RMA process. Here is a breakdown of the process.
1) Upon receiving your e-mail stating 'I CONSENT' I will process the RMA which will send you an e-mail with four things of note. One, a longer in depth version of this summary. Two, a RMA Shipping Label. Three, a RMA Label. Four, a link to order your new device.
2) The RMA Labels - The RMA Label goes in the box on top of the device and the accessories that came in the original box. The RMA Shipping Label goes on the box and the box is shipped via UPS.
3) The Replacement Cart Link - This is what you use to order your device. We ship you the device even before we receive your old one. This will put an authorization hold (not a charge) on your account, which will be released when we receive your old device. This is of course because we are sending a device before receiving the old one. If you have questions about holds, your bank would be the best to talk to about it as each bank handles them differently. For the most part this does not impact your ability to make purchases, however we have had reports some banks handle this differently.
Note: If you want your replacement device faster you can pay to expedite shipping, more details in the cart link.
Thank you for contacting us. Feel free to reply to this email and I will respond as soon as I can, you can also contact us at 1-855-83NEXUS (1-855-836-3987).
Have a great day,
Christopher
The Google Support Team