Kazuyoshi Tsutsui is Professor of Department of Biology at Waseda University. He is one of the leaders in the field of Endocrinology and Neuroendocrinology. He has discovered novel neurosteroids and neuropeptides and demonstrated their mode of actions and functional significances. He was awarded Zoological Society Prize in 2001, Farner Medal in 2008, etc. He is President of Asia Oceania Society for Comparative Endocrinology and Past President of Japan Society for Comparative Endocrinology.