Tomiichi Murayama
In the late 1980s and early 1990s, the JSP under the leadership of Takako Doi earned a record-high number of seats. However, shocked by the establishment of new conservative parties, the party's seats in the National Diet decreased significantly in the mid-1990s. Finally, the JSP dissolved in 1996. Its successor is the Social Democratic Party, a minor party only holding four representatives in the National Diet as of 2020. There have been two JSP Prime Ministers of Japan, Tetsu Katayama and Tomiichi Murayama.