[1] He was affiliated with Aoni Production at the time of his death and was known for providing the voice of both the narrator and Professor Oak/Dr.

Ishizuka was known for his deep, strong voice and was often cast in the role of older mature male characters, such as Jet Black from Cowboy Bebop, Eugene Gallardo from Tales of Rebirth and Captain Matthews in the Xenosaga trilogy.

He was also the fourth Japanese voice of Heihachi Mishima in the Tekken video game series, and the second Japanese voice for Mr. Satan in the Dragon Ball franchise, taking over both roles since the death of longtime actor Daisuke Gōri.

He has voiced the roles of Kizaru in the One Piece series, Van Hohenheim in the Fullmetal Alchemist: Brotherhood series, Zabuza Momochi in the Naruto series, Ginzo Nakamori in Detective Conan and Magic Kaito, Joseph Joestar in JoJo's Bizarre Adventure: Stardust Crusaders and JoJo's Bizarre Adventure: Diamond Is Unbreakable, as well as Bunta Fujiwara in Initial D, Ryotaro Dojima in Persona 4 and Ujiyasu Hōjō in Samurai Warriors and Warriors Orochi.

Ishizuka was also the famous voice-over actor for Liam Neeson, Laurence Fishburne and Kevin Spacey.