About us


FIELDS IP Attorneys PPC is a patent professional corporation (PPC) which was established by the merger of the former firms of FIELDS IP Attorneys and Hayashi, Doi & Associates in April of 2022.

The former firm of FIELDS IP Attorneys specialized in the fields of biotechnology and chemistry including pharmaceuticals, advanced medical technology, food science, and new advanced materials. On the other hand, Hayashi, Doi & Associates specialized in the electrical and mechanical fields including information technology (IT), telecommunication technology, and software, in addition to handling design and trademark matters. Due to the merger of the two firms, FIELDS IP Attorneys PPC will be able to provide one-stop services for the filing and prosecution of patent, utility model, design, and trademark applications as well as be able to help clients utilize, protect and enforce their intellectual property rights, regardless of the technical fields involved.

FIELDS IP Attorneys PPC also has patent attorneys of all ages, ranging from patent attorneys with more than 20 years of experience to up-and-coming young patent attorneys. By passing on the knowledge, experience and know-how of experienced attorneys to the next generation, we have created a platform where we can provide continuous and consistent IP services to our clients both now and far into the future.

In addition, the former two firms excelled at handling different technical fields, but thanks to the merger, our patent attorneys can now cooperate on specific cases by sharing each other's knowledge, experience and know-how beyond the boundaries of the offices. Needless to say, the progress of science and technology has been remarkable in recent years, and the number of inventions in boundary areas and advanced areas is increasing exponentially. For example, inventions such as the development of new advanced materials using artificial intelligence (AI) require both a background in AI and software as well as a background in new advanced materials themselves. At our new firm, patent attorneys are now in a better position to expertly handle such inventions by closely coordinating and sharing information, experience and expertise.

FIELDS IP Attorneys PPC provides complete, one-stop services for intellectual property, striving daily to meet our customers' business needs as intellectual property experts, and continuing to evolve with the ever-changing world around us.

Nobutaka Yokota, Representative Partner

Our goal

Leading our clients' IP strategy and contributing to their business

Our goal is to lead our clients' IP strategy and contribute to their business
by providing high quality IP services to precisely meet their needs.


  1. We always put our clients' interests first.

    Being useful to our clients' business is our motivation.

  2. We endeavor to meet service quality and cost.

    We work hard to offer a level of quality that goes beyond personal satisfaction to provide services that satisfy clients' expectations. On the other hand, we continually endeavor to maintain fair, transparent rates.

  3. We support our clients' business and management strategies by presenting various solutions.

    We know that there are always several solutions with regard to IP services including drafting and prosecuting patent applications, and solving patent disputes. We consider all angles and suggest various options in order for our clients to be able to choose the best solution.

  4. We devote ourselves to managing work schedules and administrative duties.

    We know that excellent attorneys' work should also be provided on schedule and be accompanied by excellent clerical support. We recognize that schedule management and administration work are part of quality services.

Our firm's name

Our firm's name means that each of our attorneys is determined to make this firm the field where our clients' business is nurtured and brought to fruition.


Tsunenori Hayashi founded Hayashi & Associates
Kenji Doi founded Doi & Associates
Two firms merged to form Hayashi, Doi & Associates
Nobutaka Yokota founded FIELDS IP Attorneys
FIELDS IP Attorneys and Hayashi, Doi & Associates merged to form FIELDS IP Attorneys PPC

Contact us

FIELDS IP Attorneys Patent Professional Corporation (PPC)
Tokyo Main Office
AIOS Nagatacho 609, Nagatacho 2-17-17, Chiyoda-ku, Tokyo 100-0014 Japan
Shin-yokohama Office
BENEX S-3 Bldg., 3-20-8, Shin-yokohama, Kohoku-ku, Yokohama-shi, Kanagawa 222-0033 Japan
Sendai Office
2-10-2, Murasakiyama, Izumi-ku, Sendai-shi, Miyagi 981-3203 Japan
Representative Partner
Patent Attorney
Nobutaka Yokota
Tokyo main office
Shin-yokohama office
Sendai office
Tokyo main office
Shin-yokohama office
Sendai office

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Merged and Founded
April 2022