Hotta holds Dphil in International Relations from the University of Sussex in 2004. Since joining IGES in 2005, he has been involved in various policy initiatives and research projects in relation to resource efficiency and circular economy such as G8’s 3R Initiative, Working Group for 3R Policies for Southeast and East Asia as well as Regional Knowledge Centre for Marine Plastic Debris at Economic Research Institute for ASEAN and East Asia (ERIA), and OECD’s Working Party on Resource Productivity and Waste. He was a lead editor of State of the 3Rs in Asia and the Pacific (2018). Hotta contributed to several key publications on circular economy and plastics in Asia and the Pacific including Circular Economy and Plastics: A Gap-Analysis in the ASEAN Member States (2019) by ASEAN and EU. Hotta was a theme leader of the policy design component of Japan’s Strategic Research Project (S-16) on Policy Design and Evaluation to Ensure Sustainable Consumption and Production Patterns in Asian Region supported by Japan's Environment Research and Technology Development Fund.