Of Counsel Nagamine served as a government official at the Ministry of Foreign Affairs for many years, dealing with diplomacy, especially cross border negotiations and dispute settlements which required application of public international law. In mid-career, he was seconded to the Cabinet Legislation Bureau to engage in the examining of Government bills to be submitted to the Diet. As a senior diplomat, Of Counsel Nagamine served in three Ambassadorial posts in the Netherlands, Republic of Korea and the United Kingdom to promote and manage important bilateral relations. After finishing his career as diplomat/administrator, he was appointed as a Justice of the Supreme Court of Japan. During his 3 years’ service at the Court, he dealt with many cases appealed before the Supreme Court and made contributions to the formation of new jurisprudence.