About us

The power of intellectual property

Rapidly advancing science and technology. A world in constant flux.
At Aihara & Partners (A&P), we stay ahead of the curve, supporting our clients’ challenges and growth on a global scale as dedicated professionals in intellectual property.

We are a medium-sized firm—neither a large-scale organization nor a solo practice.
This allows us to offer agile, flexible responses and meticulously tailored services that make full use of each member's expertise.

Our team of partners and staff, well-versed in a wide range of technical fields, works in close collaboration to provide comprehensive, one-stop support for all aspects of intellectual property—from application to strategic utilization of rights.

Three Core Policies

Earning trust through dedication. That’s why our clients come first.

In today’s world—where technology continues to advance and diversify, and corporate activities become increasingly globalized—the value of intellectual property is more critical than ever.
At Aihara & Partners, we uphold a “client-first” philosophy, and as specialists in intellectual property, including patents, we have earned the trust of a broad range of domestic and international clients.

Drawing on our in-depth knowledge of intellectual property laws not only in Japan but also across various countries, we provide highly specialized, high-quality services tailored to the unique needs of each client.

End-to-End Involvement × One-Stop Service — Striving to Be Your Comprehensive IP Partner

We aim to be a full-service intellectual property firm that provides seamless support—from the discovery and consultation phase of inventions, designs, and trademarks, to domestic and international applications, rights acquisition, portfolio management, enforcement, strategic use, and even licensing negotiations.

As corporate needs continue to diversify, close collaboration across our entire firm is essential in delivering high-level, specialized services. Our experienced patent attorneys and staff, each with deep expertise in their respective fields, work together—and when necessary, in coordination with our partner attorneys—to provide truly one-stop solutions.

We are committed to offering attentive, detail-oriented support that anticipates and meets our clients’ needs—striving always to be a trusted and dependable partner.

We value people — and the connections between them.

At the heart of our services is a deep respect for people and the connections between them.
We believe that strong internal trust and teamwork form the foundation for delivering high-quality intellectual property services.

Our patent attorneys, technical specialists, and administrative staff support one another, continually honing their individual expertise and growing together as a team.

By valuing harmony within our organization, we strive to be a trusted group of professionals who work together to deliver the best possible outcomes for our clients.

History and Corporate Overview

Aihara & Partners, Patent Professional Corporation, is the successor to NAGATO & PARTNERS, Patent Professional Corporation, which was originally founded as Nagato International Patent Office by its founder, Kanji Nagato (who stepped down in September 2022).
The firm was originally established on July 1, 1985, and reorganized as a patent professional corporation on July 7, 2004. It was renamed to its current name on October 1, 2022.

We have inherited the full scope of operations from NAGATO & PARTNERS and continue to provide a comprehensive range of intellectual property services, including domestic and international applications for patents, utility models, designs, and trademarks, as well as

Track Record of Foreign Patent Filings

We have extensive experience filing applications not only in Japan, but also in over 50 countries worldwide.
In recent years, Southeast Asian countries—where many Japanese companies are expanding—have seen a growing trend of faster patent examinations through the use of the Patent Prosecution Highway (PPH), making it easier to obtain rights.

We support parts manufacturers and other companies that have, or are planning to establish, production or R&D bases in Southeast Asia, by assisting with their patent and trademark applications in those countries.

Countries Where We Have Partnered with Local Agents

We work closely with trusted local agents in various countries, enabling us to provide meticulous and responsive support for foreign filings.
From Europe and the United States to China and Southeast Asia, we offer comprehensive support for patent, design, and trademark applications across a wide range of technical fields.

Partner Offices

We aim to be a comprehensive firm that meets the diverse needs of our clients by working in partnership with Nakamoto Sogo Law Office, which has strong expertise in corporate legal affairs and international matters (including English/Chinese contracts and legal services in English and Chinese), and with Oshimoto Patent and Trademark Office, which specializes in trademark law.

Foreign partnership

For patent, design, and trademark applications in the United States, Europe (EPC), China, South Korea, India, Southeast Asian countries, and other jurisdictions, we collaborate with carefully selected and highly competent local firms in each region.