Energy poverty, defined as the inability to fulfil adequate levels of domestic energy services, has been analysed in Japan previously. However, neither policy agendas nor official definitions of energy poverty have been established yet, resulting in the neglect of energy-poor households and other relevant aspects of this issue. This study is the first to examine the contextual factors of energy poverty in Japan, through the perspective of energy poverty vulnerabilities. The study uses a new multidimensional approach, covering the issues of affordability and accessibility to different forms of energy, as well as the effects of new technologies on the risk of energy poverty. The study develops several unexplored issues in previous literature, such as access to low-carbon energy as an issue in developed countries. The results highlight the role of location, infrastructure and household characteristics in influencing the risk of suffering energy poverty in Japan. The seasonality of energy poverty in Japan is also analysed, revealing higher rates of energy poverty in the northern regions during winter and in the southernmost region during summer. Finally, the impact of the ongoing energy transition from fossil fuels to renewable energy on energy poverty is discussed.