I already own the Japanese versions to 6 and Kiwami 2. 6 is pretty good and has a great story. Finally great to see Beat Takeshi, a legendary yakuza actor, finally added to the franchise. In addition, it features other famous Japanese actors such as Tatsuya Fujiwara (from Battle Royale and Death Note) and Shun Oguri (GTO and Gokusen). Also, Ryusei Nakao, the voice of Freeza from Dragon Ball Z is in the game.
Kiwami 2 brings back the hostess mini game once again played by Japanese adult film actresses and the song as you customize them is still present. However, the Majima game is too short.