Japan's national statistics portray a future of assured decline; as of 2005, 30 percent of men between the ages of thirty-five and thirty-nine remained unmarried and in 2010 it was reported that among men 25 to 34, 25.8% of employed men were irregular workers. This ethnographic project will examine how young Japanese men are negotiating their heterosexual masculinity in an era of fundamental socioeconomic instability that has undermined the possibility of achieving a stable, secure life course. Both the attainment and the allure of the white-collar salaryman life course—university, job, family—have been lost amidst these changes. Despite the prevailing feelings of loss, young men are contending with these challenges through the creation of new sites, socialities, and practices of sexuality and masculinity. I argue that these shifts in heterosexual masculinity are consequently changing Japan as the nation reacts to and contends with over two decades of crisis, including the bursting of the economic bubble in the mid-1990s, the precipitously falling birthrate, and the recent Tohoku and Fukushima disasters. Through 16 months of ethnographic fieldwork in Tokyo and Osaka, this project explores the significance of postindustrial and postmainstream shifts on the sites and performance of heterosexual masculinity among young Japanese men.