Prefectural elections for the Tokyo Metropolitan Assembly were held on 12 July 2009. In the runup to the Japanese general election due by October they were seen as an important test for Taro Aso's ruling coalition of the Liberal Democratic Party (LDP) and the New Komeito. New Komeito considers Tokyo as an important stronghold and had repeatedly asked Prime Minister Aso to avoid holding the two elections within a month of each other.
Campaigning officially started on July 3, 2009. The prefecture's 10.6 million registered voters (up 230,000 from 2005) were called upon to elect the 127 Assembly members in 42 electoral districts at 1,868 polling stations across Tokyo. 221 candidates had been formally registered with the Tokyo metropolitan electoral commission. The LDP and the Democratic Party of Japan (DPJ) each endorsed 58 candidates, the Japan Communist Party (JCP) supports 40 and New Komeito formally fields 23 candidates, though it has also decided to support LDP candidates in several districts. Local campaign issues included Tokyo's bid for the 2016 Olympic Games and governor Shintaro Ishihara's plan to relocate the Tsukiji fish market in 2012. The national debate over a possible ban of "hereditary" (世襲, seshū) politicians has also affected several candidates.
Tokyo's legislative election is one of only three elections for prefectural parliaments countrywide that are not held in the "unified regional election" (tōitsu chihō senkyo, last round: 2007), the other two being Ibaraki's and Okinawa's prefectural assembly elections.
Polls closed at 8:00 pm Japan Standard Time. Turnout was significantly up from 2005 and stood at 54.5 percent. The DPJ picked up 20 seats and saw 54 of their 58 candidates elected. The LDP lost its status as strongest party in the Metropolitan Assembly for the first time since 1965. Despite strong results for coalition partner Kōmeitō, the ruling camp could not defend an absolute majority (64 seats). The only electoral district where an LDP candidate received the most votes (top tōsen) was the single-member [Izu and Ogasawara] islands electoral district of former assembly president Chūichi Kawashima, a native of Ōshima town who had represented the islands since 1985.