The Supreme Court of Japan , located in Hayabusachō, Chiyoda, Tokyo, is the highest court in Japan. It has ultimate judicial authority to interpret the Japanese constitution and decide questions of national law. It has the power of judicial review, which allows it to determine the constitutionality of any law or official act.

The Constitution of Japan is the constitution of Japan and the supreme law in the state. It was written primarily by American civilian officials working under the Allied occupation of Japan after World War II. The current Japanese constitution was promulgated as an amendment of the Meiji Constitution of 1890 on 3 November 1946 when it came into effect on 3 May 1947.