Out of the 480 seats in the Lower House, 300 are elected from single-seat districts and the remaining 180 by proportional representation in 11 regional blocks.
Each voter casts two ballots — one for a candidate in their single-seat district and the other for a political party or group for the proportional representation segment.
Political groups and parties submit lists of candidates for the proportional representation system beforehand, and are allocated seats in accordance with how many votes they get. The seats go to the candidates on the lists in descending order.
A candidate who runs in a single-seat district can also be placed on the proportional representation list, but to do so the candidate must belong to a political party that has at least five Diet members or gained at least 2 percent of the votes in the previous general election.
The system gives a second chance to candidates who are unsuccessful in a single-seat district.
Even though Nippon Ishin no Kai (Japan Restoration Party) and Taiyo no To (The Sunrise Party) were created recently, both have more than five Diet members in their ranks.
Legislation aimed at cutting the number of Lower House seats by five to help rectify the disparity in the value of votes was enacted Friday. Due to the several months needed for preparation before holding an election with revised single-seat districts, voters will still elect 480 Lower House members in the Dec. 16 election.