Saegusa & Partners

IAM Research

The Patent 1000 focuses exclusively on patent practice and has firmly established itself as the definitive 'go-to' resource for those seeking world-class legal patent expertise.

Silver - Firms: prosecution

“Saegusa & Partners provides high-quality work. They have good English, are well organised, thorough and very responsive.” With almost 80 years of history, offices in Osaka and Tokyo, and a team of 29 IP experts, Saegusa & Partners has the depth and breadth of experience to truly excel in patent matters. The outfit caters primarily to the domestic clientele in non-contentious matters: from leading corporations to start-ups and academic institutions. Previously a chemical industry researcher and IP head of the Osaka University spin-off company, Masaki Morishima leads the firm’s international client and chemical departments. His international background enables him to understand the mindset of foreign patrons and assist them seamlessly. Chemist and executive vice president Takahiro Hishida represents well-known Japanese clients in non-contentious IP matters domestically and abroad.

Firm Profile

Founded in 1946, Saegusa & Partners is considered a leader among professionals and in-house counsels in Japan. Developing alongside Japan’s current patent system, the firm has grown from its beginnings in Kitahama, Osaka – one of the largest chemical and life sciences business clusters in Japan – to become one of the most renowned IP firms in the country. Saegusa, which also has offices in Tokyo steps away from the Japan Patent Office, boasts a team of 130 dedicated individuals (including around 50 IP attorneys), and can provide comprehensive coverage in technical fields ranging from stem cells to artificial intelligence.

Although the majority of Saegusa’s clients are domestic, in recent years the firm has been increasingly recognised in the international market. For example, a partner leading the chemical and biotech department has been recognised in the 2019 to 2022 editions of Who’s Who Legal as a leading Japanese patent attorney due to his outstanding service and legal expertise.

Saegusa thus works with a diverse array of international clients from various countries. These clients include many of the world’s leading companies, as well as highly active start-ups and prestigious universities. The firm assists its international clients in a variety of aspects, including conducting proceedings before the Japan Patent Office and the patent courts; providing validity and infringement opinions; and drafting English-language patent applications on the basis of inventor interviews.

With nearly 30 skilled attorneys in its patent group led by nine highly experienced partners, Saegusa strives to provide its international clients with a new experience in IP service, based on the values outlined below.

In their clients’ shoes

No borders – no attorney in Saegusa focuses only on international clients; they also assist the firm’s domestic clients with prosecution, oppositions and litigation abroad (in the United States, Europe, China and Korea in particular). In addition, the firm frequently sends hand-picked attorneys to overseas IP firms for year-long, on-the-job training programmes in order to learn the local IP practice. These invaluable, broad-ranging experiences enable Saegusa’s attorneys to provide advice on Japanese patent matters, while also putting themselves in the shoes of their international clients. A deep understanding of the differences between Japanese practice and other local practices enables the firm’s attorneys to ensure better service and thus satisfaction for all clients.

Trust based on shared values

Not merely a service provider – every attorney at Saegusa strongly believes that trust from clients enables them to provide better solutions, based on a better understanding of needs and seamless communication. Moreover, the firm’s attorneys believe that trust is built on shared values and, therefore, frequently travel abroad to meet with clients worldwide and nurture relationships. Saegusa’s core value – quality – is of utmost importance.

Communication is key

Nothing is lost in translation – international clients’ experience of patent services in Japan is often reported as frustrating because of communication problems stemming from differences in language and culture. It is for this reason that Saegusa – including the paralegals who communicate the most frequently with the firm’s international clients – strives to provide close communication while ensuring availability, friendliness, dependability, empathy and a willingness to do what’s necessary to please their international clients; every member of the firm always goes the extra mile. Saegusa combines close communication and thorough knowledge of Japanese practice to make a difference for all the firm’s clients.


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