This paper investigates the causes for the start of the cycle of environmental protest in Japan in the mid-1960s. Some argue that a broad cycle of protest starts when stimulated by sudden short-term openings in the political opportunity structure (POS). Alternately, others argue that a closed POS is more likely to generate a cycle of protest. In studying the Japanese case, this paper finds that while short term openings in the POS stimulated the broader cycle, they were not necessary for the later cycle of environmental protest. Rather, when the POS rejected their formal complaints, communities mobilized unruly protest throughout the nation. The findings support a two-stage model: initial POS openness, but later POS rejection of political demands based on this new frame.