A dataset on two decades of Japan's energy investments in Southeast Asian countries, 20 0 0-2020

Between 20 0 0 and 2020, Japan played a crucial role in trans-forming Southeast Asia's energy sector, contributing significantly to local, national, and regional development. This period saw substantial Japanese investments in various energy sources, including renewable energy initiatives and continued use of fossil fuels, while emphasising capacity development. Our research involved an extensive and system-atic inventory of secondary resources, with meticulous validation and fact-checking of critical project data. The resulting dataset provides funding amounts and details channelled through Japanese government-backed institutions and private corporations. This dataset could enhance our under -standing of Japan-supported energy infrastructure and soft-skill capacity-building projects, allowing us to analyse further how these investments were aligned with the broader economic and sustainability objectives of Southeast Asian countries. Covering investment types, funding sources, and project locations, this valuable resource is useful for scholars across disciplines. Asian studies researchers can gain insights into Japan's strategic involvement in the region, while energy studies specialists can gain a nuanced understanding of the evolving energy finance landscape. Energy policy experts can also use this data to analyse the implications of Japan's contributions to Southeast Asia's energy transition.(c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )