Modern Japanese literature emerged as Japan asserted itself as a military-industrial power from the end of the 19th through the early 20th centuries. The subject of modern literature was worthy of a seat at the table of the world’s powers, or so goes the story of a literary canon all too often focused on the legitimacy of elites. But modern literature is not only about a male alienated intellectual failing to have a satisfying relationship. During the international “red decade” (1925–1935), proletarian writers in Japan as elsewhere sought to harness and transform the technology of modern literature in order to represent the hitherto un- or underrepresented women and men, peasants and factory workers, elderly and children in order to bring the masses into consciousness of their collective power. For a decade, nearly every writer in Japan engaged the energetic but often divided proletarian movement as they sought to grasp the challenges of a rapidly modernizing society, transformation in the family and gender, dual economy, worldwide depression, and escalating imperialism. Largely overlooked during the Cold War, this important decade of modern literature has experienced a well-deserved scholarly and popular revival in a period of 21st-century precarity, protests against privilege, and questioning of media and representation. Two exemplars from proletarian literature—Hayama Yoshiki’s “The Prostitute” (1925) and Miyamoto Yuriko’s “The Breast” (1935)—offer a frame to apprehend the richness of genre, voice, storytelling, experimentation, and ethics in proletarian literature, a vital part of modern literature.