In March 1994, just months after the enactment of reform in Italy, Japan's Diet passed into law its own electoral system change, replacing single non-transferable vote (SNTV) with a straight mixed-member majoritarian (MMM) system. Under the new system, there were 300 seats elected by single-member plurality (SMP) and 200 seats elected by PR from closed party lists in eleven districts, with no compensation between the two parts. The same system survives today, except that the number of PR seats was reduced in 1999 to 180. As in Italy, the gestation of the reform was long and involved pressures both from groups within the political elite and from the public. The process can be divided into four phases, corresponding to the tenures of the four principal prime ministers to hold office during the period: Noboru Takeshita (together with his short-lived successor, Sosuke Uno), Toshiki Kaifu, Kiichi Miyazawa, and Morihiro Hosokawa.

Phase 1 Reform talk under Takeshita and Uno, 1988–1989

As Chapter 7 discussed, replacement of SNTV with an electoral system based wholly or largely on SMP was the subject of continuous, if generally low-intensity, discussion from the founding of the modern party system in 1955 until Prime Minister Kakuei Tanaka's aborted reform proposal in 1973. The hostility that met Tanaka's proposal, however, forced most reform enthusiasts to retreat. The seventh Electoral System Advisory Council, which reported in December 1972, was not replaced when its term ended.