This research explores the effects of social capital on human agency at the case of support activities by foreign residents in the wake of the Kumamoto Earthquakes in 2016. The debate about Japan’s foreign residents in times of disaster has primarily concerned the situation and needs of foreigners and subsequently addressed questions of how the host society should respond to these issues. This has developed into a perception of foreign residents as “victims” of earthquakes. The paper argues that foreign residents have the capacity to exercise their agency in times of disaster by engaging themselves in support activities contributing to Japan’s society. It shows how social networks have enabled support activities by foreign residents of Kumamoto City in the aftermath of the earthquakes. The paper concludes that social capital played significant roles in the activities by influencing the agency.