Buy on DLsite
It's up on the Japanese DLsite now.
Buy from my blog
To buy the game from me directly, first download the demo. (V6)
Then, buy the game from this site. After you've bought the game, click "back to overture interactive" for your download link. Place the file you get in the same folder as the Kurovadis demo in order to unlock the full game. Must be used with V6 (The demo listed above)