Having worked for a Japanese commercial bank, United Nations Development Programme (UNDP), and the Japanese Government, Mr. Shiihara joined the Asian Development Bank in September 2008. Since then, he has been involved in processing as well as administration of energy sector projects for such countries as Bhutan, Cambodia, Fiji, India, Indonesia, Nepal, and Papua New Guinea, among others. 

Since January 2024, he has been designated as the Project Administration Unit Head, looking after administration of all energy sector projects from Southeast Asia and the Pacific.