Dengeki Magazine ran a popular series of photo-novels called Advance of Zeta: The Flag of Titans a couple of years back. This series proved very popular and Dengeki Magazine is launching a sequel of sorts.
Not much has been revealed so far but the main Mobile Suit has been introduced. It’s called the GM Kai (Wagtail). I’m not to keen on the design so far though. Still, any new GM is good news for me. 
And woot! A tiger-striped RGC-83 GM Cannon II! Let’s hope it gets some focus to justify a HGUC release!
