This paper examines why Japanese social policy changed from the 1990s. Globalization and its accompanying trade liberalization have affected the regime of international political economy and social policies of many countries. Many previous studies on this issue focus on the U.S. or the U.K.; however, the Japanese social policy system is different from that of those countries because the roles of the companies are very important. In the 1990s and the first half of the 2000s, Japanese social policy experienced neoliberal reform due to the reaction to globalization. Japanese neoliberal reform is mainly diversification of employment types and reduction of welfare programs provided by companies. However, because of this reform, two problems have arisen. One is the increasing number of non-regular employees, and the other is a lack of social security. To solve these problems, Japan reconstructed the social policy system in the second half of the 2000s and the 2010s. This paper assumes three paths to resolving problems after neoliberal reform. Path A is reconstructing the social policy. Path B is continuing with neoliberal reform. Path C is denying globalization and encouraging protectionism. According to the result of analysis, Japan has chosen path A among these paths.