[2] Maehara was the leader of the Democratic Party of Japan (DPJ) from 2005 to 2006, and later served as Minister of Land, Infrastructure, Transport and Tourism and Minister of Foreign Affairs under the cabinets of Yukio Hatoyama and Naoto Kan, before resigning from the cabinet in March 2011 after he acknowledged receiving illegal donations from a South Korean national living in Japan.

[4][10][11] Maehara founded a new party in 2023, Free Education for All, which was broadly centrist and focused on building a coalition against the LDP.

Maehara won election to the Kyoto Prefectural Assembly in 1991 with the support of, among others, future Diet member Keiro Kitagami.

Although he initially led the party's criticism of the Koizumi administration, particularly in regards to connections between LDP lawmakers and scandal-ridden Livedoor, the revelation that a fake email was used to try to establish this link greatly damaged his credibility.

Maehara had known the woman since junior high school,[14] but her foreign nationality made the donation illegal if it had been accepted intentionally.

[16] The donation was revealed by an opposing party politician, Shoji Nishida; The Economist described the incident as a scandal based on a technicality that primarily illustrates the unsatisfactory treatment of Koreans in Japan.

Through his reliable support from conservative DP and former JIP members, Maehara comfortably won the leadership election with 60% of the points up for grabs.

Whilst the details were inconclusive, Yamao resigned from the party less than a week after the affair was reported, widely seen as an effort to halt further decline of DP's fledgling support.

[22] Maehara also faced a potential rival in Tokyo governor Yuriko Koike, who grew increasingly confident after her party's landslide win in the Tokyo Assembly elections and was rumoured of planning to form a conservative national party to face Prime Minister Shinzo Abe in the next general election.

However, despite Maehara's request, Koike imposed an ideological filter that effectively barred liberal-leaning members of the DP, such as Yukio Edano, from joining Kibō.

This led Edano to form the Constitutional Democratic Party less than three weeks before election to house liberal DP members.

Koike's multiple blunders during the campaign led Kibō to fall well short of high initial expectations, becoming the second largest opposition party behind the Edano-led CDP.

[27][28][29] Following his defeat to Tamaki, he and several other DPP parliamentarians, including former Governor Yukiko Kada, split from the group to form Free Education for All.