So far since the enactment of the Immigration and Refugee Recognition Act in 1951, the Japanese government has focused on control, and assimilation to some extent, of foreign residents in the country, leaving their integration out of theoretical and practical considerations. However, especially after the 1990s, the government made a series of amendments to the 1951 Immigration Act through which some foreign residents were allowed the extended length of stay and offered institutional support for settlement. These revisions have gained the growing scholarly attentions for the integration of foreign residents in Japan. While so-called immigrant integration has been generally understood as a two-way process involving both immigrants and a host country’s society, there is little consensus on how to measure such a process. As such, this chapter proposed a new analytical framework—Resilience Model—and applied it to the empirical analysis of the 2020 and 2022 Surveys on Foreign Residents by the Survey Research Centre in Japan. This chapter reveals two major findings. First, some foreign residents in Japan have built up an extended network of support including both the persons and/or organizations of the same nationality and Japanese, while others have only developed connections with fellow residents of the same nationality. Such a difference, in turn, will be demonstrated as meaningful to explain the varying length of stay.