Feudal Japan in 3D.
http://www.nintendoworldreport.com/news/35129
Nobunaga's Ambition for 3DS will be releasing in Japan on September 19 for 5040 yen, as announced in today's Nintendo Direct .
The game will feature branching paths and DLC as well as expected StreetPass and Spotpass features. There is currently no word on a release outside of Japan