Russia’s unprovoked attack against Ukraine entails significant implications to Japan’s security and its surrounding environment. How is Japan responding to Russia’s use of force? What are the drivers of its responses? This case study examines official speeches by Japanese leaders and government senior officials, government announcements, opinion polls, and analyses by Japan experts to understand Tokyo’s perceptions and responses to Moscow’s military attack against Kiev. Seen from Tokyo, the invasion of Ukraine is not only an attack against the rules-based international order but also a manifestation of Japan’s security concerns regarding China’s growing military capabilities and closer Russia-China alignment, especially the potential use of military force to change the Indo-Pacific region’s power balance. This article also finds that Tokyo’s response to Russia-China alignment and the Ukraine invasion continues to be wedded to an approach is characterized by a mixture of engagement, resilience, and deterrence, aiming at both Russia and the growing Russia-China alignment.