武藏野市
Tsuchiya entered national politics after resigning from his position as mayor of Musashino, Tokyo in 2005 to run against the then Deputy President of the Democratic Party of Japan, Kan, for the House of Representatives seat in the Tokyo 18th district. Although Tsuchiya lost in the run-off, he was still elected under the party-list proportional representation system. Kan and Tsuchiya have since continued to face off in House of Representatives elections, with Kan holding on to the single member district seat through the 2009 general election, and Tsuchiya capturing the single member district seat in the 2012 general election and the 2014 general election.