Shinjiro Koizumi was born in Kanagawa Prefecture in 1981 and after graduating from the College of Economics, Kanto Gakuin University, he went on to obtain an MA from the Graduate School of Arts and Science, Columbia University in 2006. After working as a researcher at the Center for Strategic and International Studies (CSIS), he changed careers to become a secretary to former Prime Minister Junichiro Koizumi in 2007. In August 2009, he was elected to the House of Representatives, and is now serving his fourth term. In September 2013, he became Parliamentary Vice-Minister of Cabinet Office and Parliamentary Vice-Minister of Reconstruction Ministry. In October 2015, he became the Director, Agriculture and Forestry Division, LDP, he was involved in agricultural reform. Since August 2017, he has been become Chief Deputy Secretary-General.