Neither are mine.
All I could get from the site was "contact customer service".
If you're having it delivered in Japan and they use practically any of the major courier services, you're probably in luck. You'll just have to ask customer service to specify the delivery date/time when they send it.
If it comes early and you're not there, it's no big deal. The delivery guy will leave a form in your mailbox and you can easily arrange redelivery at a time convenient for you.