Looking at the Timeline of Streetview, it says "Selected Japanese caves and mines including Okubo-mabu and Akiyoshi-do limestone cavern" were added February 14th. Finding the streetviews of them on GE or GM is impossible: it simply doesn't show up. However, once you have the link to the files, you can see them (but in the .jp version of google maps).

Here is the streetview link for the Akiyoshi-do cavern: http://maps.google.co.jp/maps?ll=34....31.302593&z=17

And the streetview link for the Okubo-mabu cave: http://maps.google.co.jp/maps?ll=35....132.44663&z=17

Adding that to the streetview section of this website however does not generate a streetview issue. I don't know the coding behind this, but is it possible to get these links to work for this website?