Democratic Party of Japan

The Democratic Party of Japan (Japanese: 民主党, Hepburn: Minshutō) was a centrist to centre-left, liberal or social-liberal political party in Japan from 1998 to 2016. It was the main opposition to the Liberal Democratic Party from 1998 to 2009 and from 2012 to 2016, as well as the ruling party of Japan from 2009 to 2012. It is not to be confused with the now-defunct Japan Democratic Party that merged with the Liberal Party in 1955 to form the Liberal Democratic Party. It is also different from another Democratic Party, which was established in 1947 and dissolved in 1950.

The party's origins lie in the previous Democratic Party of Japan, which was founded in September 1996 by politicians of the centre-right and centre-left with roots in the Liberal Democratic Party and Japan Socialist Party. In April 1998, the previous DPJ merged with splinters of the New Frontier Party to create a new party which retained the DPJ name. In the 2000 general election, the party won 127 seats, firmly establishing it as the main opposition party. In 2003, the party was joined by the Liberal Party of Ichirō Ozawa and won 177 seats in the 2003 general election. 2004 House of Councillors election, the DPJ won a seat more than the LDP. The party lost 64 seats in the 2005 general election, with its seats being decreased to 113. Nevertheless, the party won further seats in the 2007 House of Councillors election, becoming the largest party in the House of Councillors and creating the first divided Diet since 1999.

Following the 2009 election, the DPJ became the ruling party in the House of Representatives, defeating the long-dominant LDP in a landslide and gaining the largest number of seats in both the House of Representatives and the House of Councillors. During its time in office, the DPJ was beset by internal conflicts and struggled to implement many of its proposed policies. Legislative productivity under the DPJ was particularly low, falling to levels unprecedented in recent Japanese history according to some measures. However, the DPJ implemented a number of progressive measures during its time in office such as the provision of free public schooling through high school, increases in child-rearing subsidies, expanded unemployment insurance coverage, extended duration of a housing allowance, and stricter regulations safeguarding part-time and temporary workers.

The DPJ lost its majority in the House of Councillors in the 2010 election. The party was ousted from government by the LDP in the 2012 general election. It retained 57 seats in the lower house, and still had 88 seats in the upper house. On 27 March 2016, the DPJ merged with the Japan Innovation Party and Vision of Reform to form the Democratic Party (Minshintō), which in turn merged with the Party of Hope on 7 May 2018 to form the Democratic Party For the People, while a significant amount of members split to form the Constitutional Democratic Party of Japan on 3 October 2017 and on 15 September 2020.

The Democratic Party of Japan (DPJ) was formed on 27 April 1998. It was a merger of four previously independent parties that were opposed to the ruling Liberal Democratic Party (LDP)—the previous Democratic Party of Japan, the Good Governance Party (民政党, Minseitō), the New Fraternity Party (新党友愛, Shintō-Yūai), and the Democratic Reform Party (民主改革連合, Minshu-Kaikaku-Rengō). The previous parties ranged in ideology from conservative to social-democratic. The new party began with ninety-three members of the House of Representatives and thirty-eight members of the House of Councilors. Moreover, the party officials were elected as well at the party convention for the first time; Naoto Kan, former Health and Welfare Minister was appointed as the president of the party and Tsutomu Hata, former prime minister as secretary-general.

On 24 September 2003 the party formally merged with the small, centre-right Liberal Party led by Ichirō Ozawa in a move largely considered in preparation for the 2003 general election held on 9 November 2003. This move immediately gave the DPJ eight more seats in the House of Councilors.

In the 2003 general election, the DPJ gained a total of 178 seats. This was short of their objectives, but nevertheless a significant demonstration of the new group's strength. Following a pension scandal, Naoto Kan resigned and was replaced with moderate liberal Katsuya Okada.

In the 2004 House of Councillors election, the DPJ won a seat more than the ruling Liberal Democrats, but the LDP still maintained its firm majority in total votes. This was the first time since its inception that the LDP had garnered fewer votes than another party.