Okiayu Ryoutarou is K's voice in Gravitation. He was born on November 17th, 1969 (He is 33 as of 2002) in Fukuoka, Japan. He is currently working for Aoni Production and he's done the voices of some other popular anime. Some of his other anime roles include Kimura Takurou from Di Gi Charat, Treize Kushrenada from Gundam Wing, Matsuura Yuu from Marmalade Boy, and Tigers Eye from Sailormoon SuperS. In addition to those, he's done Brad Crawford from Weiss Kreuz, Inova from Magic Knight Rayearth, Akatsuki Nagare from Martin Successor Nadesico, and Kimura Takumi from an episode of Kamikaze Kaitou Jeanne. <_< Aside from voice acting, he also sings and has a couple of solo CDs out as well as a part in the Marmalade Boy soundtrack.
I adore Okiayu Ryoutarou's voice as various characters in anime. K's voice is no exception. :) He has a pretty low voice for some of his characters, and it definately brings out their personalities. K's voice is pretty much what you'd imagine, a low and yet smooth tone that fits various moods and scenes. He can speak English pretty well too, and the accent's simply adorable as well. I love hearing him speak English, especially at tense moments in Gravitation where he'll sprout a word or two, ease the tension and have me laughing. XD