The Japanese man behind Professor Oak and the narrator of the Pokémon TV series, Unshō Ishizuka, has passed away from esophageal cancer. He was aged 67.

Aoni Production, his talent agency, today reported that Ishizuka passed away on August 13. The agency’s website noted that he was under medical care prior to his death.

Known for his authoritative, deep and strong voice, Ishizuka had been in the Japanese voice acting industry since 1984. His most prominent role was as Professor Oak and the narrator in the Japanese Pokémon TV series. You might have also heard him as the Japanese voice for Jet Black from Cowboy Bebop, the senior Joseph Joestar in JoJo’s Bizarre Adventure: Stardust Crusaders and JoJo’s Bizarre Adventure: Diamond Is Unbreakable. He also took the place for some roles — namely Mr. Satan from the Dragon Ball series — of fellow voice actor Daisuke Gōri, who died in 2010.

It is currently unknown what will happen to his roles in the Pokémon TV series, of which he has been part of since it first aired in 1998. Anime News Network reports that his relatives have held a private wake and funeral, and that a public farewell ceremony is in the works.