This article examines Hoshi Pharmaceuticals' attempt to cultivate cinchona, the raw material for the antimalarial drug quinine, in the mountains of Taiwan during the 1930s and 1940s. Hoshi Hajime, the founder and president of the company, pitched a “humanitarian” vision of quinine self-sufficiency for Japan's empire centered on providing indigenous tribes with food and education in exchange for their land and labor. This vision appealed to a wide range of actors, including police officials and government bureaucrats, who argued over how to civilize the aboriginal population; botanists and agricultural companies, who pondered over how to further exploit the untapped potential of the island's tropical environment; and doctors and bureaucrats concerned with the supply of quinine to civilian and military personnel as the wartime empire expanded into Southeast Asia. Hoshi's cinchona cultivation project was a metaphor for the technocratic and utopian promise of Japan's colonial empire. By tracing the project from its earliest beginnings to its postcolonial afterlife, I examine the complex connections between science, capitalism, and nationalism, situating colonial concerns in a web of global influences and inspirations.