Writes Kawanaka, "Video is a medium of image as well as sound. Walking on a gravel road with a camera, the crunch sound is captured in real time. Such [an] observation seems obvious, but as a filmmaker, the ability to record sound in real time was very new to me. Referencing a can-kicking game I played as a child, I followed the rolling can and recorded the resonant sounds of the can hitting the ground." 　　In 1968 Nobuhiro Kawanaka co-founded the Japan Filmmakers Cooperative, a national distributor for independent and experimental films, and later played a key role in experimental film in Japan as a founding member of Underground Center and Image Forum. He was also a key member of Video Hiroba, which was founded in 1972. He was the original edotor of the film magazine Monthly Image Forum. He created the Video Letter Exchanges series (1979-) in collaboration with Sakumi Hagiwara, among other works.