In 2018, Japan established the Specified Skilled Worker (SSW) program to address the acute labor shortages brought by rapidly progressing population aging and declining birth rates. The SSW is built upon the guest worker program known as the Technical Intern Training Program (TITP), and, notably, it is embedded in the global trend of liberalizing guest worker programs. It creates a three-step pathway for low-skilled temporary workers hired through the TITP to change employers, to reunite family in Japan, and to eventually apply for permanent residence. The SSW also shifts the labor mobility governance from brokerage agencies back to the hands of the state. Drawing on data collected over 14 months of fieldwork in Japan, I show that the broker and employer control over labor mobility persists through both TITP and SSW, leading to a persistent state of migrant worker precarity. I analyze, on the one hand, how the restrictive controls over labor mobility – wielded by brokers and employers – subject workers to labor disputes and precarious situations (e.g. infringing on female workers’ reproductive rights); on the other hand, I examine how migrant workers cooperate with humanitarian actors and navigate complex institutional rules on job changes, status upgrades, social welfare attainment, and labor dispute resolutions. I demonstrate that the freedom to change employers under SSW is difficult to obtain on the ground. The shift of mobility governance from brokers to the state does not eliminate control held by brokers and employers, who withhold required documents for job changes. The state erects barriers to balance labor supply among industries that have impeded workers’ job changes across industries (such as from agriculture to the food industry). Moreover, workers’ precarity persists due to inadequate legal protections and regulations on broker activities – an outcome that differs little from the TITP. These substantial discrepancies between intentions and outcomes of policy reforms point to major challenges in liberalizing guest worker programs: the lifting of structural constraints over labor mobility built into guest worker programs; the resolution of the inherent conflict between permitting employer changes and meeting employers’ labor demands; and, the regulation of brokers and employers to protect workers and alleviate their vulnerability. As Japan is facing daunting demographic challenges that resemble those encountered in many other countries in the developed world, my dissertation has strong policy implications for the management of global competition for low-skilled and semi-skilled migrant workers.