Hideaki Yamashiro is a mammalian sperm cryobiologist with more than 10 years of experience in the field. It has been an interesting experience working for Japan International Cooperation Agency (JICA), Japan Overseas Cooperation Volunteers in Botswana, Africa, for developing livestock management by using sperm. After that, he tried to develop the cryopreservation method of the Red maasai sheep sperm at Consultive Group on International Agricultural Research (CGIAR) of the International Livestock Research Institute (ILRI) in Kenya. He received his PhD at Tohoku University in Japan. Postdoctoral training has been done at Institute for Biogenesis Research, Department of Anatomy and Reproductive Biology, John A Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, USA. Research interest is now focused on gametes and fertilization biology, assisted fertilization, biotechnology including sperm freezing in mammals at Niigata University in Japan.