In tackling the COVID-19 pandemic, Japan took a relatively relaxed approach where enforced restrictions on people’s everyday lives with penalties were extremely limited. This chapter characterizes such a response as a ‘cooperation-based approach’ that relied heavily on citizens’ voluntary commitment and coordination at the grassroots level. Following a discussion on the initial condition of Japan’s policy for infectious disease control, the chapter provides a brief overview of how the national government settled on a legislative framework on which to base the response strategies. Also discussed is the confusion triggered by a two-tiered approach where the national government was to declare a ‘state of emergency’ while the prefectural governors were given the authority to address requests to their citizens. As the key to building collective cognition that led to a high level of voluntary commitment by citizens, the chapter highlights three symbols and signals that alerted citizens: the government’s announcement of school closures, penetration of the phrase ‘san-mitsu,’ and the voices of civil society organizations that brought to the fore serious situations of vulnerable populations.