Gōshi Hosono has been a member of the House of Representatives since 2000. After moving among several non-LDP and non-socialist parties, including the Democratic Party of Japan (民主党), Democratic Party (民進党), and Party of Hope (希望の党), Hosono won the 2021 general election as an independent. After the election he officially joined the LDP; in 2019, he joined a parliamentary group composed of other independent and LDP members. .

In each of his former political parties, he served as a significant leader, such as party executive or minister. As a member of the Party of Hope (希望の党), he played a main role in writing and publishing partial constitutional drafts for Chapters 3, 7 and 8 in February 2018. While the draft for Chapter 8 (Articles from 92 to 95) proposed expanding local autonomy, the draft for Chapter 3 (Article 26) and 7 (Articles 83 and 89) aimed to provide free education for children of all ages, from infants to high-school students, relaxing the limitation of usage of public funds.

Hosono also attached a PDF of his essay for a journal, Chūō Kōron (中央公論), published in May 2017, to his blog entry; in the essay, he proposed constitutional revision dealing with education, national emergencies, and local governance.