He graduated from the Tokyo University of Foreign Studies with a degree in Chinese language in 1975 and joined Nippon Steel the same year.

[1] After leaving Nippon Steel Hamada joined the Center for Strategic and International Studies in Washington, D.C., becoming a Fellow and associate director in 1987.

Hamada contested the Tottori at-large district of the national House of Councillors at the July 2010 election as a candidate for the Liberal Democratic Party.

On 27 June 2011, whilst still a member of the opposition LDP, Hamada was offered a position in the government of Naoto Kan as Vice-Minister for Internal Affairs and Communications.

Hamada became a Vice-Minister for Foreign Affairs in Noda's cabinet and remained in the position until the DPJ were defeated by the LDP in the December 2012 general election.

Instead Hamada received a nomination to contest the summer 2016 election from the national proportional representation block as an Initiatives from Osaka candidate.

[8] Hamada nominated for the July House of Councillors election as an independent candidate in the six-seat Tokyo at-large district.