The party was founded by
Takashi Kawamura, then the mayor of Nagoya, and registered with the
Aichi Prefectural electoral commission on 26 April 2010. At a press conference held on the same day, Kawamura emphasized the point that the greatest support that politicians can provide to citizens is a reduction in taxes. Sato had lodged her resignation with the party in March in order to provide support to Genzei Nippon's candidates in the Nagoya city council election, but her application was put on hold while DPJ officials considered expulsion instead. Two more DPJ members of the House of Representatives,
Koki Kobayashi from the
Tokyo proportional representation block and
Toshiaki Koizumi of the
Ibaraki 3rd district, left the party to join Genzei Nippon in August 2012. On 31 August, the three representatives joined with fellow DPJ defector
Tomoyuki Taira to form the
Genzei Nippon-Heian voting block within the House of Representatives, with Koizumi as the leader. DPJ representatives
Atsushi Kumada (
Osaka 1st district) and
Tomohiko Mizuno (
Southern Kanto block) joined Genzei Nippon in October 2012, giving the party five Diet members, the minimum requirement for registration as an official party. The party was registered with Kawamura as the leader on 31 October 2012. On 17 October 2023, during the first press conference and party meeting of the newly-founded
Conservative Party of Japan, it was announced that Genzei Nippon would be affiliated nationally with the Conservative Party, with Kawamura becoming the Conservative Party's vice president. Around the time of the election, reports emerged of internal tensions between Hyakuta and Kawamura regarding the party's management. In September 2025, Diet member Yuko Takegami, a close ally of Kawamura, left the party, citing disagreements with Hyakuta and Kawamura's marginalization in leadership decisions. Later that month, the party announced it was severing ties with Genzei Nippon, and Kawamura was removed from his position as co-leader. Kawamura was reportedly considering forming a new party in response. ==Presidents==