Takeshi Shudō (首藤剛志) (August 18, 1949-October 29, 2010) was the original director and a frequent writer for the Pokémon anime series. He left during the Johto League; episode 244 was his final episode.
Reading his blogs reveal a lot of What Could Have Been for the anime series. His novels also go into detail on the anime's world, which paints it in a...different light than what many fans would think. He also wrote Pokémon: The Birth of Mewtwo radio drama which was later adapted into Pokémon: The First Movie, as well as the It's a White Tomorrow, Team Rocket! radio drama.
Tragically, he died of a subarachnoid hemorrhage at age 61 in 2010. However, he is receiving a Posthumous Credit as a writer for Mewtwo Strikes BackEvolution, despite the movie coming out nine years after he died.