Japan is extremely vulnerable to energy and environmental crises. Because of that, its energy and environmental policies are increasingly integrated, stressing adaptation as the route to decarbonizing mitigation. Its policy entrepreneurs build on lessons from Japan’s March 11, 2011, natural and nuclear disasters, and subsequent events. Their initiatives have resulted in an array of inclusive organizations and comprehensive policies that cross over formerly siloed policy domains. Energy sectors are being deregulated and networked through smart technology. Decarbonizing and spatially compact communities have become the locus of Japan’s “Society 5.0” industrial policy. Society 5.0 is integrated with “national resilience” and related measures that stress resilience against seismic hazards and climate change. Japan’s expanding energy-environmental industrial policy is key to meeting the country’s Paris Agreement commitments.