水岡俊一

Shunichi Mizuoka is a Japanese politician serving as the leader of the Constitutional Democratic Party of Japan since January 2026. A long-time member of the House of Councillors, he has been elected four times and previously served as the party's House of Councillors caucus chairman and as an advisor to the Prime Minister under the Noda Cabinet. With a background as a teacher and an official within the Japan Teachers Union, Mizuoka has focused his political career on education policy, labor rights, and social welfare. He is known for his advocacy regarding the revision of income restrictions for high school tuition support and his support for the introduction of selective separate surnames for married couples.