Motomiya joined JR East in 1991 and has held a variety of managerial positions mostly in planning and lifestyle service business fields. From 2007 to 2010, he was a manager of Investment Planning Dept. and Terminal Planning Dept, working as president at JR East Aomori Business-Development Company Co., Ltd. 2010-2013, where his job was to revitalize regional cities through agricultural industrialization by processing, logistics and marketing. The expertise gained on this assignment was instrumental in his appointment as general manager of the Regional Revitalization Division in 2013. Since June 2014, Motomiya has been engaged in the Shinagawa Development Project, currently deputy general manager of the Shinagawa and Life Business Development Division, where his role as project manager is to envision and create new urban environments.