Tokyo 6th district is a constituency of the House of Representatives in the Diet of Japan (national legislature).

[2] As of September 2012, 486,353 eligible voters were registered in the district, giving them the third lowest electoral weight in the country.

[3] Before the electoral reform of 1994, Setagaya was part of Tokyo 3rd district, a three-member single non-transferable vote (SNTV) constituency.

Since its creation, the urban district had been dominated by opposition candidates until the landslide "postal privatization" election of 2005 when Liberal Democratic candidate Takao Ochi was able to defeat Democratic incumbent Yōko Komiyama by a slim margin.

After Democratic representative Kōki Ishii had been stabbed to death in 2002 by a rightwing activist,[4][5] a by-election was held on April 27, 2003.