I have been told Japan Post has sold out all their sheets. I will contact & attempt to confirm later tonight with Japan Post.
To call from USA:
011 Overseas code from USA
81 Country Code
0570-046-111 Telephone number where English accepted. Japan 14 hours ahead of US Central time. (GMT+9)
UPDATEI just noticed that what looks like the Japan 1/2 sheet is not but rather a version printed for USA??? Not available in Japan even though Japan postage??? The USPS did same thing with the France Joint issue of Myles & Piaf. The French sheet was different than what was available in France, the US version of France stamp was not available in France even though it was a French stamp??? The sheet issued in France was different.
Look above in this section on pg 1 by
wt1 of Japan image of their sheet and compare to USPS Japan 1/2 sheet look-alite. Why are they doing this??
2nd UPDATE Japan Post does not allow calls from overseas to customer service???? We rebuilt their country and they don't allow us to telephone their Post Office?
3rd UPDATE Well I ended up having to purchase from a dealer at 12.50 GBP (about $18.34 USD) each or a little over 2 1/2 times face.

Amazing how a country's stamps sell out so fast. One would think Japan would have printed more to satisfy the demand from their country as well as US giving the theme of this issue. Same thing with US and the press sheet issue.