In 1987, he started practicing medicine in the Department of Surgery of Tokyo Women's Medical University (TWMU) and received Ph.D. in Medical Science at TWMU with a research topic: Relationship between colonic diverticulosis and peristalsis. From 2006, he was Senior Lecturer and Division Chief of Department of Gastroenterological Surgery of Yachiyo Medical Center of TWMU. In 2016 he became Chief of Department of Surgery at National Hospital Organization Murayama Medical Center in Tokyo, Japan.