The presence of hundreds of thousands ethnic Koreans in Japan, or "zainichi Koreans," is one of the visible legacies of Japanese colonialism. A surprising and influential group among zainichi Koreans that persists to this day is Chongryon, the only pro–North Korean diasporic group based in a capitalist society. Chongryon historically represented the central grassroots force seeking to liberate Koreans from Japan's imperial and neo-imperial influences. At the heart of the Chongryon community stands a political organization equipped with a central bureaucracy in Tokyo, with a headquarters in nearly every prefecture. Often called a de facto embassy of North Korea, the Chongryon organization has, in effect, functioned as a state within another state—operating hundreds of schools, banks, hospitals, business associations, publishing houses, and many other institutions across Japan. Based on extensive archival research and nearly 250 original interviews collected with co-researcher KumHee Cho, who was raised within the Chongryon community, Sayaka Chatani offers a sweeping social history of this secretive, protective community in xenophobic Japanese society. Weaving together personal accounts and situating them in a multi-layered, transnational political context, the book offers a finely textured, intimate narrative of the community's tumultuous history and decolonial praxis. Through the stories of Chongryon, this book provides a bottom-up analysis of power politics among zainichi Koreans and reshapes our understanding of Japanese history, Korean history, and the Cold War in Asia.