히토쓰바시 대학
Sekino was born in 1949 in Tokyo. While a student at Hitotsubashi University, he cofounded and participated in a university team that descended the entire length of the Amazon, thereafter travelling around South America. He received a B.A. in law from Hitotsubashi University in 1975 and an M.D. from Yokohama City University School of Medicine in 1982.