Born on February 25, 1950 in Tokyo, Japan.

He graduated from Yokohama City University School of Medicine in 1974 and completed his residency training in gynecology at the Tokyo University Hospital in 1979. In 1983, he was a postdoctoral fellow at Miami University School of Medicine where he conducted research on reproductive endocrinology. Dr. Kawai then took a postgraduate course in Internal Medicine at the University of Edinburgh. Upon returning to Japan, he opened Kawai Medical Clinic in Susukino, Yohohama, in 1989. Dr. Kawai is married and has three children.