Siliconera

FromSoftware announced Dark Souls II for Japan. Like Dark Souls, Namco Bandai will handle the Western market as the game’s publisher, but FromSoftware will retain publishing rights for Japan.

In Japan, Dark Souls was only released for PS3 in even though an Xbox 360 version was released overseas by Namco Bandai. Dark Souls II will be a multiplatform title in Japan with PS3, Xbox 360, and PC versions announced for the region.

It interesting to note since Konami Japan decided not to release Xbox 360 versions of multiplatform titles like Silent Hill: Downpour and Metal Gear Rising: Revengeance.

http://www.siliconera.com/2012/12/10/dark-souls-ii-wont-be-a-ps3-exclusive-in-japan/

yep.  fromsoftware is pretty small and likely didn't have the manpower to do it at the time.  kind of surprised 360 japan will get this one.  in the west it makes perfect sense but in japan specificallyl i can't see it getting enough sales to make it worth their time.  a wiiU version would probably be a better use of their time.