Yuki's seiyuu is Inoue Kazuhiko. He was born on March 26th, 1954 (he's 48 as of 2002). He was born in Yokohama, Kanagawa and works for the Ohsawa Jimusho Company. He's done way too many Anime roles to list, but some of the most prominant ones are Kusanagi Mamoru of Blue Seed, Rokou of Fushigi Yuugi, Pazusu of Vampire Princess Miyu, Utsuki Hakase of Pokemon, Shigure Takimi of the Rurouni Kenshin movie, and Kigai Yuuto from X. Eiri Yuki looks almost exactly the same as Kigai Yuuto. <_< Aside from voice acting, he also sings and has a couple of CDs out.
Kazuhiko does a marvelous job being Eiri Yuki. His voice is very rough and deep, sometimes full of emotion. When Yuki gets angry, the voice turns to a low growl and has gruffy sound. He can speak English pretty well too.^-^ However he does have an accent. The "thanks" sounds like "sanks." XD I don't think there could be a better voice for Yuki. He really brings out and expand Yuki's personality like a seiyuu should. It gives you an opinion of the character itself.^-^