Of Counsel

东京 + 81.3.6800.1816

Koichi Inoue advises multinational companies on complex tax issues in transactions involving multiple jurisdictions and helps plan and implement the restructuring of their global operations in a tax-efficient manner. Koichi has practiced in the field of international transactions, investments, and dispute resolutions with primary emphasis on Japanese tax law for more than 30 years. His tax experience covers analysis and advice to a wide range of clients in relation to their commercial transactions and restructurings. He also represents taxpayers in complicated administrative proceedings and tax litigation.

Koichi's experience spans a variety of industries, including pharmaceuticals, telecommunications, manufacturing, real estate development, software, private equity, and reinsurance companies. Koichi's recent engagements include tax consultation for PAG Asia I LP in connection with the sale of its 25% interest in Universal Studios Japan to Comcast for $2.3 billion.

Koichi is listed as Band 1 (Japan, tax: domestic) in Chambers Asia-Pacific and one of Tier 1 leading individuals (Japan, tax) in The Legal 500 Asia Pacific. He is also named in The Best Lawyers in Japan for tax and Who's Who Legal: Corporate Tax. Koichi regularly writes and lectures on tax and related subjects. He is a coauthor of Taxation of International Transactions and Overseas Investments (2019) and The Interrelation between Tax Treaties and Domestic Tax Law (2nd ed. 2011). Koichi also has served as a lecturer at Aoyama Business Law Graduate School.


  • Materion acquires H.C. Starck's electronic materials portfolio for $380 millionJones Day advised Materion Corporation, a world leader in high performing advanced materials, in connection with the acquisition and financing of H.C. Starck Solutions' industry-leading, electronic materials business, located in Newton, Massachusetts ("HCS-Electronic Materials") for $380 million.
  • Riverside sells Y InternationalJones Day advised The Riverside Company in the sale of Y International, Inc., a Japanese bicycle retailer, to Daiwa PI Partners Co., Ltd.
  • Japanese wire manufacturer and its U.S. subsidiary defend against alleged patent infringement regarding wire technologyJones Day secured a final judgment of non-infringement and invalidity in favor of a Japanese wire manufacturer and its U.S. subsidiary in a patent infringement case related to coil wire technology in the Central District of California.
  • MassMutual International sells 85.1 percent of MassMutual Japan to Nippon LifeJones Day advised MassMutual International LLC in its sale of 85.1 percent of the shares of MassMutual Japan, MassMutual's wholly-owned life insurance and wealth affiliate, to Nippon Life for JPY104.2 billion (approximately US$955 million).
  • Shiseido acquires Olivo LaboratoriesJones Day advised Shiseido Americas Corporation, a subsidiary of Shiseido Co., Ltd., a leading global cosmetics company, in connection with the acquisition of substantially all of the assets of Olivo Laboratories, LLC, a startup advancing the dermatological field through proprietary biomaterials technology.
  • GE Digital acquires IQP CorporationJones Day advised GE Digital in its acquisition of IQP Corporation, a start-up operating in Israel, Japan, and the U.S. that provides a no-code or low-code IoT app builder, with a visual interface available on mobile, tablet, and PC, includes data apps, and is installable on public cloud, private cloud, and on premise.
  • PAG Asia Capital sells remaining stake in Universal Studios Japan to Comcast NBCUniversalJones Day acted as lead counsel to PAG Asia Capital Ltd. in the sale of its remaining stake in Universal Studios Japan as part of the ¥254.8 billion (US$2.3 billion) sale of Universal Studios Japan to Comcast NBCUniversal, an owner and operator of world-renowned theme parks.
  • Athersys licenses regenerative medicine therapy to Healios for treatment of stroke in JapanJones Day acted as intellectual property and tax counsel in the collaboration of Athersys, Inc. and Healios for the development and commercialization of novel stem cell therapy treatments, using Athersys' MultiStem cell.
  • Athersys licenses stem cell therapy to ChugaiJones Day advised Athersys, Inc. as licensor, in connection with its collaboration with Chugai Pharmaceutical Co. to further develop and commercialize Athersys' proprietary MULTISTEM® stem cell therapy in Japan for the treatment of ischemic stroke.
  • Tokyo Electron attempts $29 billion merger of equals with Applied MaterialsJones Day represented Tokyo Electron Limited in its proposed $29 billion merger of equals with Applied Materials, Inc., which, if completed, would have created a global innovator in semiconductor and display manufacturing technology based in The Netherlands and dual listed on NASDAQ and the Tokyo Stock Exchange.
  • Omron sells equity interest in Power SystemsJones Day advised Omron Corporation (TSE-listed) in its sale of its equity interest in Power Systems, Ltd., a maker of flexible, slim pack, electrical double layer capacitors, to Ioxus, Inc., a U.S. company in the energy storage business for clean energy, EV, transportation, and other applications.
  • RHJ International sells its 77.9% ownership of Niles Co. to Valeo for ¥15.4 billion (€135 million)Jones Day advised RHJ International SA in its sale of its 77.9% interest in Niles Co., Ltd., a Japanese auto parts manufacturer, to Valeo SA, a worldwide leader in the interior controls market, for a total cash consideration of ¥15.4 billion (€135 million).
  • Riverside completes sale of GTI Diagnostics to Gen-ProbeJones Day represented The Riverside Company in connection with its sale of GTI Diagnostics, an in-vitro diagnostics specialist, to Gen-Probe Inc., a global leader in the development, manufacture, and marketing of molecular diagnostics products and services.
  • SanDisk enters new joint venture with Toshiba for flash memory manufacturing in JapanJones Day advised SanDisk Corporation in the formation of a new Fab 5 joint venture with Toshiba Corporation to construct a state-of-the-art NAND Flash memory fabrication facility and to continue to jointly develop new technologies in order to enhance their competitiveness in the memory business.
    • November 2021
      IFA (International Fiscal Association): OECD Pillar 2 - Minimum tax
    • September 2018
      ジョーンズ・デイ セミナー:国際的なライセンス契約に関する契約上および税務上の留意点
    • August/ September 2018
    • September 2018
    • June / July 2018
    • February / March 2018
    • November / December 2017
    • October 2017
    • August/ September 2017
    • February / March 2017
    • November / December 2016
    • August 2016
    • February 2016
    • August 2015
    • July 2015
      国際税務研究会 :国内税法の主要制度と租税条約の適用を踏まえた-海外進出企業のための税務リスクマネージメント入門
    • July 2015
      国際税務研究会 :国内税法の主要制度と租税条約の適用を踏まえた-海外進出企業のための税務リスクマネージメント入門
    • May 2015
    • October 2014
    • September 2014
    • March 2014
      BLCCJセミナー:Offshore Assets Reporting System
    • December 2013
      BDO Japanセミナー:簡易な移転価格ソリューションの活用
    • September 2013
    • August 2012