Sega has announced Yakuza Ishin (which translated means Yakuza Restoration) during its "Yakuza Character General Election" in Japan yesterday.
While it's being suggested that game will get a Japan-only release, there were no platform or release dates mentioned during the announcement of the game (which will feature a character called Ryoma Sakamoto), but according to Siliconera more details will be revealed in the next issue of Famitsu.