OSAKA Office



Head of International Client Department | Co-head of Chemical Department


Education and Personal History

Kyoto University, Master of Science – MS, Applied Life Science

Practice and Professional Experience
Masaki has more than a decade of experience in patent prosecution. Prior to joining Saegusa & Partners in 2008, he served for over 5 years as the head of the IP department of an Osaka University spin-off company that focused on regenerative medicine, after gaining valuable work experience in the chemical industry as a corporate researcher for Lion Corporation.
Masaki is the head of our International Client Department, and, as co-head of our Chemical Department, oversees the work of nearly a dozen attorneys and office staff. He works with a diverse array of clients from various chemistry and biotech fields, including specialty chemicals, pharmaceuticals, fibers, foods, personal care products, diagnostics, enzymes, and stem cells. His particular technical specialties include adhesives and coatings; OCA films; refrigerants; surfactants and emulsifiers; biomarkers; genetic engineering; cell culture technologies; and cell therapy.
He is highly experienced in drafting and prosecuting patent applications. Additionally, having represented clients on many occasions, Masaki is also experienced in oppositions and nullity proceedings before the JPO, as well as appeals before the IP High Court. He frequently provides infringement and validity opinions.
In order to study EPO practice in depth, Masaki undertook an intensive, year-long training program at Munich- (Vossius & Partner, Hoffmann Eitle) and London-based (Marks & Clerk) IP firms. Additionally, to assist Japanese clients doing business overseas, he frequently attends oral proceedings before both the Opposition Divisions and the Boards of Appeal of the EPO. This experience enables Masaki to provide European clients with advice on Japanese IP matters, while ensuring better understanding and satisfaction by doing so from the European practitioner’s perspective, particularly in view of the differences between the two regions.
In recent years, a significant portion of his work has been for large multinationals filing patents and/or launching products in Japan. He often travels to Europe to meet with clients, and is a regular contributor regarding Japanese patent matters to Mitteilungen der deutschen Patentanwälte, the monthly intellectual property law journal published by the Chamber of German Patent Attorneys (Vorstand der Patentanwaltskammer).
Recognized in IAM Global Leaders 2022
IAM says: At the top of his field, Masaki Morishima combines an extensive understanding of technical, legal and business issues with a personable approach that is loved by inventors and foreign associates alike. He drafts applications that pave the way for long-term success and is highly sought after by international companies looking to secure their interests in Japan.
Recognized in IAM Patent 1000 – 2021 | Recommended Individuals: prosecution
A peer praises Masaki’s “individual approach,” and states that they were “impressed by Masaki’s knowledge and practical approach,” and “truly appreciate that I communicate directly with Masaki and not via paralegals.”
Recogized in WWL 2021 as a Leading Japanese Patent Attorney
WWL says: Masaki Morishima is widely recognized as “a really excellent practitioner” who brings “excellent technical suggestions” to cases.

Recognized in IAM Global Leaders 2021

IAM says: Masaki Morishima is a beacon for international companies seeking to protect innovations in Japan; he also gives domestic followers the benefit of his extensive EPO expertise. A precision drafter and prosecutor of patents, he is an adept handler of contentious matters.
Recognized in IAM Patent 1000-2020 | Recommended Individuals: prosecution
A peer praises Masaki’s “well-structured and smart advice,” and states that they were “extremely satisfied with the style and quality of his comments and suggestions.”
Recogized in WWL 2020 as a Leading Japanese Patent Attorney
WWL says: Masaki Morishima is inordinately talented in patent prosecutions and has experience in various industries, from life sciences to pharmaceuticals.
Recogized in WWL 2019 as a Leading Japanese Patent Attorney
WWL says: Masaki Morishima is a well-recognised figure in the Japanese market where he impresses with his considerable experience handling patent prosecution proceedings.
Select Publications
– Author. “Japan: Successes and Setbacks of the “Nation built on IP“– Problems and Expectations,” Mitteilungen der deutschen Patentanwälte, March 2017, pp. 110-113
– Coauthor. “Japanese Supreme Court Decision on Patent Term Extension Application,” Mitteilungen der deutschen Patentanwälte, April 2016, pp. 162-163