Takehito Koyasu (子安武人 Koyasu Takehito, born May 5, 1967 in Yokohama, Kanagawa, Japan) is a very popular and prolific Japanese voice actor.
According to the Anime News Network, as of April 2008, Koyasu is the most prolific seiyū in Japan with voice acting roles in over 345 anime series. He is also part of the seiyū quartet Weiss which also consists of Weiss Kreuz voice castmates Shinichiro Miki, Tomokazu Seki, and Yuuki Hiro. He used to work for Production Baobab.
Koyasu is known for his deep, smooth voice, which often lands him on roles that are either villains or lonely bishōnen. Occasionally, though (as in the case of Mitsurugi Hanagata from Saber Marionette J, Ryo Kuroyanagi from Yakitate!! Japan), Bobobo-Bo-Bobobo, Kei Itoshiki Zoku Sayonara Zetsubo Sensei he voices lively characters. He is also well known as the voice of Rezo the Red Priest and Copy Rezo in the first season of the Slayers anime as well as Pesche Guatiche in Bleach and Daisuke in Ranma 1/2.