	H. D. Karunaratne wrote many books using the exposure and insight he gained over the years in Japan, titled, A Journey in Harmony: Sixty Years of Japan-Sri Lanka Relations (2012), Internationalization of Sri Lankan Entrepreneurship: A Study of Sri Lankan Immigrant Entrepreneurs in Japan (2009) and Distant Neighbors at Work Place: A Study of Sri Lankan Migrant Workers in Japan (2007). H. D. Karunaratne has been a member of Japan Society of International Development, Graduate School of International Development , Nogoya University Alumni Association, and East Asian Economic Association. And also he has been functioning as a member of South Asian Federation of Japanese Graduates’ Alumni Association.