Haha it's the one that came out in English last year -
http://www.gamestop.com/psp/games/hakuoki-demon-of-the-fleeting-blossom/97906
It was really good! I deliberately went for Kazama though, because let's face it - that man is amazing! :D
Eventually I'm going to replay for the other endings...Probably Heisuke and Hijikata...But none can even come close to Kazama.
You know how in visual novels, there's always a "bad" ending?
Kind of like the ending of the School Days anime. There were different endings in that visual novel, but they chose to use the bad ending in the anime.
In Hakuouki, I think Kazama's ending was the "bad" visual novel ending (don't worry - it's nothing like School Days). :( You'll see what I mean when you play it; but it is still extremely awesome! And, of course, there's a bit of fanservice. XD