Professor and Chairman of Pediatrics, a Vice Dean of Medical School at Niigata University Graduate School of Medical and Dental Sciences, 
Associate Professor of Pediatrics at University of California San Diego (UCSD)
Board Member of the Japan Pediatric Society, the Japanese Pediatric Infectious Disease Society, the Japan Infectious Disease Society, and the Japanese Vaccinology Society
Published more than 150 articles in peer-reviewed journals in the field of Pediatrics and Infectious Diseases, including New England Journal of Medicine, Lancet Infectious Diseases, Clinical Infectious Diseases, Journal of Infectious Diseases, Pediatrics, Vaccine, etc. 
Currently serves as an Editorial Board member of Pediatric Infectious Disease Journal.