Japan is mobilizing all its policy capabilities for energy transition from fossil fuels to renewable energy and hydrogen energy from the perspective of realizing carbon neutrality by 2050. Among them, the overseas development and return of hydrogen energy to Japan and the domestic green hydrogen development are making great progress since the announcement of the basic hydrogen strategy in December 2017. Japan promotes the green growth strategy (December 2020) as a national strategy to achieve the 2030 GHG reduction target of 46% (compared to 2013) (NDC) and to realize ‘carbon neutrality by 2050’. Japan's green growth strategy sets 14 areas as key development industries, including offshore wind power, hydrogen, nuclear power, automobiles and batteries, semiconductors, and information & technology. It also presents action plans in the key 14 areas such as R&D, demonstration projects, introduction expansion, and self-reliance/commercialization according to the growth stage of each area. In this World Economy Brief, we would like to explore which part of Japan's energy transition policy and green growth strategy the Korean government will refer to in order to achieve the task of realizing carbon neutrality by 2050, and cooperate with Japanese government.