[1][4] Yuriko Koike won the 2016 Tokyo gubernatorial election as an independent candidate, and left the LDP in June 2017 to found a new local political party, Tomin First, which won a majority in the 2017 Tokyo prefectural election along with its coalition partner, Komeito.

Koike was hospitalized on 22 June 2021 due to severe fatigue, however she was discharged on 30 June and made surprise appearances on 3 July, the final day of campaigning, to campaign in support of Tomin First candidates in various districts across central Tokyo.

However the LDP/Komeito coalition failed to win an outright majority of seats, an outcome which was widely described as a poor showing for the LDP and a manifestation of public dissatisfaction with Prime Minister Yoshihide Suga's handling of the COVID-19 pandemic and the delayed 2020 Olympic Games.

Some analysts attributed Tomin First's unexpectedly strong result to the continuing popularity of Tokyo Governor Yuriko Koike, whose policies and personal image form the backbone of the party's appeal, despite Koike no longer serving as the leader of the party.

[4] The regional Tokyo Seikatsusha Network and Osaka-based centre-right Nippon Ishin no Kai both maintained one seat each in the Assembly.