Tatsuya Oishi (尾石 達也 Oishi Tatsuya) is a Japanese animator, director and storyboard artist at Shaft. He is the director of Bakemonogatari and the Kizumonogatari films. Despite only working on a small fraction of the series, he is largely responsible for setting the unique style the anime adaptation has become known for.
After development started on the Kizumonogatari adaptation soon after Bakemonogatari was completed, he fell in a developmental slump while deciding how to properly adapt the story. Because of this, Tomoyuki Itamura has taken his place as director ever since Nisemonogatari.
Four years past its initially planned release date, the Kizumonogatari adaptation was finally to be released as a trilogy of films starting in 2016 as his first major work since Bakemonogatari in 2009.