Koji Yamamura provided the voice for the character Father in the 2007 animated short film Franz Kafka's A Country Doctor. This film is an adaptation of the Franz Kafka short story, which Yamamura also directed, wrote, and edited. His role in this project is one of a limited number of voice acting credits in his career.

While Yamamura has occasionally contributed voices to animated works, such as the role of Japanese Tourist in the 2005 film Frank & Wendy and Yohann Kipling in Kipling Jr. from 1995, he is primarily recognized as a highly celebrated and influential Japanese independent animator and filmmaker. Born in Nagoya in 1964, he studied painting at Tokyo Zokei University. In 1993, he founded his own studio, Yamamura Animation, Inc., with his wife.

Yamamura's body of work, which he typically directs, animates, and writes, is known for its diverse techniques and surrealist themes. His 2002 short film Mt. Head was nominated for an Academy Award for Best Animated Short Film and won the Grand Prix at the Annecy International Animated Film Festival. Franz Kafka's A Country Doctor itself is a major achievement in his filmography, having won the Grand Prize at the Ottawa International Animation Festival in 2007. These films and others, like The Old Crocodile, are distributed internationally and have secured his reputation as a key figure in independent animation.