The Supreme Court of Japan was established in the aftermath of World War II, as part of a broader set of reforms mandated by the Allied Occupation forces. The new court was envisioned to replace the previous judicial system that was deeply intertwined with the militaristic government, thus paving the way for a democratic governance structure. Designed to be the highest court in the land, its formation was a significant step in promoting justice and ensuring that all legal processes adhered to the new Constitution adopted in 1946. The establishment of the court on August 4, 1947, marked the beginning of a new era in Japanese jurisprudence.

Comprising a Chief Justice and several Associate Justices, the Supreme Court was vested with the authority to interpret the Constitution and ensure that any laws passed by the Diet were compliant with it. The judicial reforms also led to the adoption of a more rigorous and independent judicial system, fostering greater public trust in the rule of law. Initially operating under the framework provided by the constitution, the court has since resolved numerous cases and has had a lasting impact on the legal standards in Japan, establishing precedents in various legal fields, which continued to shape the country's legal framework.

Among its notable functions, the Supreme Court plays an essential role in judicial review — a power which allows it to invalidate laws or executive actions that conflict with the constitution. This reinforces the idea of checks and balances within the government. The court's decisions often resonate far beyond the specific cases it adjudicates, influencing legislation and public policy in Japan. The establishment of the Supreme Court was a vital step toward strengthening the legal foundation of Japan, helping to guide the nation in its transition to a democratic society.