It seems that Japan really gets all the good stuff. Aside from the,
Windows 7 Whopper form Burger King Windows 7 users in Japan have also got a new theme that is voiced by their popular Seiyuu idol, Mizuki Nana, along with an
'officially sanctioned by Microsoft' OS-tan, Nanami Madobe.

While the theme is only available by pre-ordering Microsoft's latest operating system and is localized for Japan users only, people over at hongfire were able to release a copy with an English fix.
It's a pretty much an official custom theme made for Windows 7 users in Japan.

Want the theme? Just download :
Nanami Official ThemeSource :
Atmaxplorer