Dr. Koyama joined the Institute of Energy Economics, Japan (IEEJ) after completing a Master's degree at the Graduate School of Waseda University in 1986. He was appointed Director at IEEJ in 2007 and Senior Managing Director in 2020, and has served as Chief Economist since 2011. He assumed his current position in June 2026. He received a Ph.D. from the University of Dundee in the United Kingdom in 2001. His PhD thesis is “Japan’s Energy Strategies Towards the Middle East”. He is also a Visiting Professor, Graduate School of Public Policy, University of Tokyo; an Adjunct Professor, Institute of Innovative Research, Tokyo Institute of Technology; a Visiting Senior Fellow of Institute for International Economic Studies (IIES); and a member of the International Advisory Board, Rapidan Group, a Nonresident Fellow at the Baker Institute for Public Policy, Rice University. His areas of expertise include energy security and energy geopolitics. He is the author of numerous books and publications on international energy affairs, energy geopolitics, and the evolving global energy landscape. In July 2023, he received The OPEC Award for Research.

Yukari Yamashita joined the Institute of Energy Economics, Japan (IEEJ) in October 1985 and was assigned to the Energy Data and Modelling Center (EDMC) upon completion of her graduate studies at the University of Tsukuba. She became an IEEJ Board Member, Director in charge of EDMC (2011), then Managing Director (2020) and holds her current position since June 2026. Her work focuses on quantitative analyses of energy as well as climate change mitigation and energy efficiency policies. She has contributed to international energy cooperation through organizations such as the IEA, APEC, ERIA, and IPEEC. She also served as the President of the International Association for Energy Economics (IAEE) in 2020, following her active involvement as an IAEE board member. She was awarded an eternal IAEE membership for her contributions.