Pacifism has been the cornerstone of Japan’s identity in the post-1945 era. In the light of its changing threat perception in the post-Cold War period, Japan has been increasingly pursuing autonomy in the security domain while stretching the limits of its pacifist identity. It has hence sought to build a strong technological base to support its latent military capabilities. This article attempts to contextualise Japan’s pursuit of autonomy in outer space amid growing security competition in the domain. It discusses the legal and organisational changes that have allowed for a growing involvement of Japan’s Self-Defense Forces in operating space assets. The potential counterspace applications of major technological capabilities shown by Japan in the civilian and commercial space sectors are assessed. The article surmises that Japan, which has a global reputation as a benign space power, can continue to refine its latent counterspace capabilities amidst a pursuit of autonomy, without straying much from its pacifist traditions.