This study contextualises the background of Japan’s “carbon neutrality and net-zero” (CNN) policy announced in October 2020, thereby identifying important changes in the country’s climate policy between 1990 and 2020. Using four research questions, four main findings were extracted from a narrative technique-based analysis of Japan’s policy documents related to CNN. The following are the findings: [i] the framing of climate change as a “climate crisis” by influential Japanese climate stakeholders was a key motivation for Japan to formally announce its CNN policy in October 2020, [ii] pressure from the international community and the political leadership of the Yoshihide Suga administration are essential factors that led the Japanese government to change its stance and announced this policy, [iii] Japan unintentionally delayed announcement of the policy until 2020 due to the concern among Japanese climate stakeholders about the problem of fairness in Kyoto Protocol’s emission reduction targets, and [iv] this delay was also due to Keidanren’s (or business sector) consistent opposition to the introduction of regulatory schemes. These results emerge for the first time in a study of Japan’s CNN politics, particularly in terms of the broader context of climate politics. Finally, we offer a possible explanation for Suga’s deliberate announcement of the CNN policy. This opens up space for future research to complement our study by providing important indicators on the trajectory of this important policy.