Until 2009, Japan’s attitude towards domestic agricultural policy reforms had been one of compliance with the guidelines provided by the WTO, which requests that member countries reduce their aggregate measures of support by trimming trade-distorting (amber box) support and/or transforming traditional agricultural subsidies to decoupled ones. However, in 2010, Japan repealed the 2007 reforms and implemented a new direct payment program called the Income Compensation Program, which has led to obvious trade-distorting effects. The present paper provides a comprehensive picture of how and why Japanese agricultural policy has changed in recent decades.