Some years ago the Japanese Greatest Hits version of Tenchu: Wrath of Heaven featured a making of video. It features interviews with the developers at K2, producer at Activision Japan and the soundtrack composer. Reimaru was so kind to translate it from Japanese to English for us.
Because the entire video is too long for YouTube, I had to split it into two parts. Part 1 is at the top and part 2 at the bottom.