The quote certainly sounds familiar, and I think that it might be in either the 2ed Eldar book or possibly in the Codex Imperialis book from the 2ed game set. I don't have access to those right this moment, but I'll check them when I get back home. 

I think that the relation between the Eldar and Japan is more tenuous then between the Eldar and Tolkien though; there are some very clear parallels between Elves and Eldar, right down to some of the naming used. Unfortunately I don't know much about feudal Japan, so I'm going to spend a bit of time brushing up on that and see what parallels exist.   15:28 EST, May 12 2005.