Motoi Sasaki graduated from the University of Tokyo and started his career in the Japanese national government in 1979. In the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), he held several senior-level positions including Director of Personnel Division, Deputy Director-General of Housing Bureau, Vice-Director-General of Road Bureau, Deputy Minister for Construction, Engineering and Real Estate Industry. He served as Director-General of Land Economy and Construction Industries Bureau since 2012 before being appointed as the Vice-Minister for Infrastructure in 2014.