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Senior Statespeople
Provided by Hidetoshi Masunaga
Intellectual property law and tax law
Case highlights:
- Case of a claim for realizing one person one vote of the national elections as required by the Constitution; Since 2009, we have filed lawsuits nationwide that involved plaintiffs of all 289 single-seat constituencies for the Lower House and all 45 constituencies for the Upper House in each and every national election and have obtained a total of 164 high court and branch high court rulings and 11 Supreme Court rulings (10 Grand Bench rulings and 1 Petty Bench ruling) by November 2025. As a result of such rulings, the disparity of voting value has now been reduced from 3 times to 2 times in the Lower House and from 5 times to 3 times in the Upper House. Currently, the case for the 2025 Upper House election (the disparity of 3 times) is pending before the Supreme Court (the 11 High Courts have ruled “unconstitutional” and 5 High Courts have ruled ”constitutional” with indicating the disparity in the Upper House must be rectified as the same level of the Lower House. The SC ruling to be delivered in 2026.
- Case of a claim for nullification of correction of corporate tax to JPY 25.2 billion (Tokyo High Court judgment 2006/03/15 admitted the claim.)
- Case of a claim for a reasonable remuneration for employee’s invention (Blue LED) by Dr. Shuji Nakamura, Nobel prize laureate in Physics 2014. The Tokyo District Court 2004/01/30 ordered company to pay JPY 20 billion as a apart of the consideration for transfer of the patent.
Admitted in Japan (1973), Washington D.C. (1981), New York (1984).
Article concerning “Vote-Value Disparity in the Upper House” (Hanrei Jiho 2456-125, 2020/11/11）
Book “Litigation under the Governance Theory of Population Proportional Election Ⅳ” (Nippon Hyoron Sha Co., Ltd., 2023/9/30)
Book “Litigation under the Governance Theory of Population Proportional Election Ⅲ” (Nippon Hyoron Sha Co., Ltd., 2021/5/3)
Book “Litigation under the Governance Theory of Population Proportional Election Ⅱ” (Nippon Hyoron Sha Co., Ltd., 2020/09/30)
Book “Litigation under the Governance Theory of Population Proportional Election” (Nippon Hyoron Sha Co., Ltd., 2020/03/31)
Article “Two Major Issues in the December 19, 2018 Decision of the Supreme Court of Japan Grand Bench” (Hanrei Jiho 2403-130, 2019/06/21)
Japanese / English
Columbia University
LL.M.
1979
The University of Tokyo
B.E.
1973
The University of Tokyo
LL.B.
1965
Provided by Chambers
Hidetoshi Masunaga has significant expertise in handling contentious matters in the Tokyo District Court, High Court and Supreme Court. He is particularly experienced in advising on corporate tax disputes and IP infringement litigation.
Provided by TMI Associates
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