His areas of expertise include national security, U.S. politics, Japan-U.S. relations, and geopolitics. He holds Ph.D. in International Public Policy from Osaka University.
He has been a researcher at the Institute for Foreign Policy Analysis (IFPA) at the Fletcher School, a visiting researcher at the RAND Corporation, a researcher at the Nakasone Institute for International Peace Studies
He served as a policy secretary to former Prime Minister Toshiki Kaifu, senior research fellow at the National Institute for Defense Studies (NIDS) and Director of the National Policy Research Institute.
He tought at the Faculty of Law, Hokuriku University as professor and was Professor and Director of the Institute for International Studies at Takushoku University.
Alongside of his academic career, he concurrently served public office, including Special Advisor to Kanagawa Prefecture (in charge of US base issues), Visiting Researcher for the House of Councillors Committee on Foreign Affairs and Defense, and Visiting Researcher at the Japan Institute of International Affairs (JIIA).
Under the Prime Minister Shigeru Ishiba's cabinet, he served as Special Advisor to the Cabinet Secretariat (in charge of foreign affairs and security) from November 2024 until his retirement in September 2025.