In her early work Friends of Minamata Victims - Video Diary (1972), Nakaya filmed a sit-in in front of the Chisso Corporation headquarters in central Tokyo with a handheld video camera. The demonstrators were protesting the company's mercury pollution of waters, which had led to human deformities and deaths. Using a battery-powered television monitor that Nakaya installed at the site of the sit-in, protesters were able to play the filmed video footage directly. The work demonstrated the power of video to influence people’s actions. The immediate feedback allowed the protesters to reflect directly on their action and its effect, and to react to it immediately.