According to the law, the mission of the ministry is "to aim at improvement of the profits of Japan and Japanese nationals, while contributing to maintenance of peaceful and safe international society, and, through an active and eager measure, both to implement good international environment and to keep and develop harmonic foreign relationships".

Under the 1947 constitution, the cabinet exercises primary responsibility for the conduct of foreign affairs, subject to the overall supervision of the National Diet.

As the chief executive and constitutionally the dominant figure in the political system, the prime minister has the final word in major foreign policy decisions.

The handling of specific foreign policy issues is usually divided between the geographic and functional bureaus to minimize overlap and competition.

After World War II, these requirements were changed as part of democratic reform measures but foreign service continued to be a highly regarded career.

The vital importance of foreign affairs expanded to affect virtually every aspect of national life in postwar Japan, and the multiplicity of agencies involved in external affairs continued to be a source of confusion and inefficiency in the formulation of foreign policy.

The Diplomatic Bluebook (外交青書, Gaikō Seisho) is an annual report produced by the Ministry outlining the government's foreign policy and assessment of international political trends.