Katsuhiro Arai: Attorney at Law, US Patent Agent, Japanese Patent Attorney

Katsuhiro Arai

Tel: (949) 457-8296

Fax: (949) 457-8297

Email: [email protected]

Legal Areas of Emphasis

Patents and Trademarks

Technical Areas of Emphasis (Patents)

  • Chemical
  • Mechanical
  • Semiconductor Fabrication
  • Pharmaceutical

Professional Profile

Professional Profile

Katsuhiro Arai is a solo practitioner located in Orange County, CA., specializing in chemical and mechanical patent prosecution.

Mr. Arai worked for seven years in research and development at a major flour milling company in Japan.  Seeking a career centered on the cutting edge of science while using his English language skills, in 1986 he began working at Wakabayashi Patent Agency in Tokyo, handling domestic patent applications as well as foreign filings including U.S. filings.  Mr. Arai passed the patent bar in Japan in 1993, to qualify as a patent attorney.  In 1994 he moved to the U.S. to join Knobbe, Martens, Olson and Bear, LLP (now Knobbe Martens), representing Japanese corporations and patent firms in a wide range of U.S. and foreign patent matters.

While maintaining a full-time work schedule, Mr. Arai attended Chapman University School of Law, and was admitted to the bar in 2004.  In 2008 he opened this office as a solo practitioner, serving a wide variety of corporate and individual clients in patent and trademark matters.


  • 2001 – Juris Doctor, Chapman University School of Law
  • 1980 – Bachelor of Science in Food Engineering, Tokyo University of Fisheries (Now Tokyo University of Marine Science and Technology)

Admissions and Qualifications

  • American Bar Association
  • State Bar of California
  • Registered to practice before the US Patent and Trademark Office
  • Registered to practice before the Japan Patent Office and Japanese Courts in patent and trademark prosecution cases
  • Registered to practice before Japanese Courts in foreign law matters (2008 only)

Professional Memberships and Affiliations

  • American Bar Association
  • Orange County Patent Law Association
  • Japan Patent Attorneys Association
  • Orange Business Network

Articles, Speeches, and Seminars

  • “Differences between US and Japanese Patent Disclosure Requirements”, International Legal Strategy, Vol. VIII-7, 1999 (co-author)
  • “Can the Difference between the United States and Japan in Business Method Patent Practice Be Eliminated?”, International Bar Association, Newsletter Vol. 8, No. 2, 2000
  • “Types of Business Method Easier to Obtain U.S. Patents”, International Legal Strategy, Vol. IX-1, 2000
  • US Intellectual Property Seminar in Tokyo and Osaka, Japan, 2004

Japanese Language Proficiency

  • Ayako Peters: Attorney at Law U.S. Patent Agent

  • Yuki Honjo: U.S. Patent Agent

  • Kozue Larson:

  • Kristine Arai: Office Manager