Ms. Kawaguchi has been a Member of the House of Councillors for the Liberal Democratic Party since 2005. She was Co-chair of the International Commission on Nuclear Non-Proliferation and Disarmament from 2008 to 2010; Special Adviser to the Prime Minister of Japan, responsible for foreign affairs, from 2004 to 2005; Minister for Foreign Affairs from 2002 to 2004 and Minister for the Environment from 2000 to 2002. Previously, Ms. Kawaguchi was a Managing Director of Suntory Ltd, Director General of Global Environmental Affairs at the Ministry of International Trade and Industry, and Minister at the Embassy of Japan to the United States.

Ms. Kawaguchi holds an M.Phil in Economics from Yale University and a BA in International Relations from the University of Tokyo. In 2008, Ms. Kawaguchi was awarded Yale's Wilbur Cross Medal.