6/25/2020 Details of 1999 (Gyo-Tsu) 35 | Judgments of the Supreme Court voters or population per each member of the Diet between constituencies reaches 1:2 or more, the equal value of the vote should be regarded as being breached. This is because, in such cases, in substance, it means that one voter has got two or more votes against the one man one vote principle. 2) Admittedly, the equality of the value of the vote is not the only and absolute criterion for designing the election system; there is room for the Diet to determine the system by considering other policy factors. In such cases, provided that such factors are worth being considered legitimately under the Constitution and the reasonableness of the actual decision of the Diet can be acknowledged as an exercise of its discretion, depending on the level of discrepancy, there may be instances where it is not automatically unconstitutional even if the equality of the value of votes has been affected. Therefore, when such a situation arises, the purpose and the reason for the Diet adopting such a system, in what way these goals and reasons can be considered legitimately under the Constitution should be examined, and ultimately, the extent of the infringement on the equality of the value of votes and the result of the above examination should be considered overall as well as the reasonableness of the exercise of discretion by the Diet, and the constitutionality of such infringement should be determined. 3. Unconstitutionality of the provision on demarcation of constituency boundaries in the present case 1) According to the National Census of Population closest to the amendment conducted in October 1990, the difference of population between constituencies is at the maximum 1:2.137 and the Survey closest to the election at question in this case in October 1995, was 1:2.309. The number of constituencies in which the discrepancy exceeded 1:2 was 28 according to the former survey, and reached 60, according to the latter census. Therefore, the provision on demarcation of constituency boundaries in the present case has evidently infringed the equal value of votes. 2) Then, the problem of what purpose or reason the Diet has taken into account when adopting such a system and whether they can be legitimately taken into account under the Constitution, and whether the adoption of such a system can be regarded as a reasonable exercise of discretion by the Diet should be addressed. (1) It is evident that the primary reason for the discrepancy exceeding 1:2 is the adoption of the 'plus one' system as provided by Article 3 para.2 of the Law on Constituency Council. Based upon the result of the Census conducted in October 1990, the adoption of this system in itself resulted in the discrepancy of maximum 1:1,822 at the prefectural level (comparison of the population of Tokyo, 11,855,563, divided by 25 (number of seats) which results in 474,223 and the population in Shimane Prefecture whose population 781,021 divided by 3, results in 260,340). Considering the fact that in each prefecture, this had to be further divided into constituencies, it was evident already at this time that it was difficult to keep the discrepancy less than 1:2. (2) If, instead of adopting this 'plus one' system, the 'maximum remainder system' (a system in which the population of a block is divided by the result of the total numbers of population nation-wide being divided by the total number of seats, and the same number of seats as the integer part of the result are allocated to each block, while remaining seats are allocated in the order of the size of the decimal part of the result) to be applied to all 300 members of the House elected from small constituencies, based upon the result of the October 1990 Census, it is evident that the maximum discrepancy at the prefecture level would have remained at 1:1.622 (comparison of the population in Kagawa Prefecture 1,023,412 divided by the number of seats 2 which results in 511,706 and in Tottori Prefecture 615,722 divided by the number of seats 2, results in 307,861). Therefore, it was not difficult to keep the discrepancy less than 1:2, even by considering further allocation at the city, district, town and village level. (3) The Law on the Establishment of the Constituency Council, on one hand, provides that constituencies should be demarcated on the https://www.courts.go.jp/app/hanrei_en/detail?id=458 9/23