This chapter introduces the global challenge of energy poverty, highlighting that over 760 million people lack electricity despite technological progress. It examines international efforts, such as the United Nations’ Sustainable Development Goals, and the role of renewable energy in addressing this issue, while acknowledging technical and socioeconomic barriers. The chapter contrasts energy poverty in developing nations, focused on accessibility, with developed nations, where affordability is key. Focusing on Japan, it explores unique vulnerabilities, including low energy self-sufficiency, high costs, and limited research compared to other developed countries. Key gaps in understanding energy poverty in Japan, such as outdated data and insufficient regional focus, are identified. The chapter sets the foundation for investigating vulnerabilities, resilience strategies, and deeper insights into energy poverty in Japan, contributing to the global goal of sustainable energy access for all.