Japan’s fast-start finance (FSF) commitment is one of the largest amongst developed countries, but it is important to consider the contents of this commitment. Japan has played a significant role in global efforts to finance climate change activities in developing countries, and its FSF commitments account for almost half of the FSF that developed countries have pledged for 2010-2012. However, it is essential to better understand the broad range of instruments and activities that the government includes in its FSF, as different governments consider different types of finance to constitute FSF, so self-reported figures are not directly comparable between countries.