To comprehensively investigate how regional household contribute to national carbon emission, this paper evaluates both the direct and indirect Japanese household carbon-based emissions by using an environmentally extended input-output table as well as the regional household consumption inventory. The results indicate that the household sector is the key driving force behind Japan's emissions, and it accounts for approximately 80% of the country's total emissions when indirect emissions are included. Moreover, significant regional differences exist in terms of the carbon footprint, which is in part caused by household and fuel-type differences found across the country. Finally, this paper suggests that the impact of regional household and fuel-type differences on Japan's overall carbon footprint should be a primary focus when practitioners design customized strategies to decarbonize Japan at the subnational scale.