As far as I know, this cover was officially up on Amazon yesterday… 7 days before the release date. Deliberate or coincidence? 😄
EDIT: Is it just me or is Mizuki Nana Official Website down? I have not been able to access it for several hours now.
^Wasn’t just me, but looks like the site is back now. :3
EDIT2: Just found out the cover was posted on Nana-san’s official website since the 12th… Only that it was a smaller version. XD;;