I don't know if there's a seiyuu version, but there's a full version (4min 21) of it sung by Suara, or at least I think it is, can't remember where I downloaded it from.
Also, there's the one sung by Emi Motoda from the Utawarerumono PC game:
http://www.play-asia.com/paOS-13-71-...6nt-43-9v.html