Company lists · Data refreshed September 2026

Top 25 Intellectual property law firms based in Japan

RevenueBase identified 86 intellectual property law firms headquartered in Japan as of September 2026 and tracks 516 professional contacts across them, including 114 with verified work emails. Tokyo is the largest hub.

This list covers intellectual property law firms headquartered in Japan, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 14, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 14, 2026 86% judged on-target in blind review
86Companies
516Contacts tracked
114Verified emails
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The 25 largest intellectual property law firms based in Japan

Ranked by team size
Top 25 of 86 intellectual property law firms based in Japan, ranked by team size, largest first. Data refreshed Sep 14, 2026. RevenueBase Smart Search rates how each company's information relates to intellectual property law firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceTokyo, JapanHQ checked Sep 14, 2026501-1,00058 contacts →

Indirect evidence

“SHIGA International Patent Office is one of the largest IP firms in Japan with more than 140 patent and trademark attorneys.”

Source: RevenueBase Database · checked Sep 14, 2026
2Indirect evidenceChiyoda-ku, JapanHQ checked Sep 14, 2026201-50031 contacts →

Indirect evidence

“SUGIMURA & Partners, founded in 1923 as Sugimura International Patent & Trademark Attorneys, is a leading IP firm.”

Source: RevenueBase Database · checked Sep 14, 2026
3Indirect evidenceMinato, JapanHQ checked Sep 14, 202611-5030 contacts →

Indirect evidence

“NGB Corporation is a legal services company based out of Minato, Tokyo, Japan.”

Source: RevenueBase Database · checked Sep 14, 2026
4Strong evidenceShinjuku-ku, JapanHQ checked Sep 14, 202651-20022 contacts →

Strong evidence

“Our Firm: SONODA & KOBAYASHI, an intellectual property law firm, offers dependable legal services for intellectual property in Japan and in China.”

Source: RevenueBase Database · checked Sep 14, 2026
5Strong evidenceTokyo, JapanHQ checked Sep 14, 202651-20019 contacts →

Strong evidence

“Our main work areas are litigation, intellectual property law, business rehabilitation and insolvency, corporate compliance matters, international legal matters, M&A, finance law…”

Source: RevenueBase Database · checked Sep 14, 2026
6Indirect evidenceChiyoda-ku, JapanHQ checked Sep 14, 202651-20019 contacts →

Indirect evidence

“SONDERHOFF & EINSEL PATENT OFFICE Shin-Marunouchi Center Buillding 18th Floor 1-6-2 Marunouchi, Chiyoda-ku Tokyo Japan Tel:+81-3-5220-6500 (Main) Fax:+81-3-5220-6556 Website…”

Source: RevenueBase Database · checked Sep 14, 2026
7Partial evidenceTokyo, JapanHQ checked Sep 14, 20261-1016 contacts →

Partial evidence

“This law firm is one of the top, in the field of technology legal (IP/IT) matter.”

Source: RevenueBase Database · checked Sep 14, 2026
8Strong evidenceShibuya-ku, JapanHQ checked Sep 14, 202611-5010 contacts →

Strong evidence

“SKIP is the diminutive of SK INTELLECTUAL PROPERTY LAW FIRM.”

Source: RevenueBase Database · checked Sep 14, 2026
9Indirect evidenceTokyo, JapanHQ checked Sep 14, 20261-1010 contacts →

Indirect evidence

“Authense IP is a group of patent attorneys with abundant experience in domestic and foreign IP enrollment, that enables us to provide quality service working closely with clients…”

Source: RevenueBase Database · checked Sep 14, 2026
10Strong evidenceTokyo, JapanHQ checked Sep 14, 202611-5010 contacts →

Strong evidence

“CREO Law & Intellectual Property was established in 1978, and now has a full-time staff of approximately 50 personnel, including 13 patent attorneys, 3 lawyers and a native…”

Source: RevenueBase Database · checked Sep 14, 2026
11Indirect evidenceChiyodaku, JapanHQ checked Sep 14, 2026201-50010 contacts →

Indirect evidence

“Established in 1998 by Mr.”

Source: RevenueBase Database · checked Sep 14, 2026
12Strong evidenceTokyo, JapanHQ checked Sep 14, 202651-2009 contacts →

Strong evidence

“On January 1, Primeworks IP Attorneys began services to assist clients with intellectual property related matters.”

Source: RevenueBase Database · checked Sep 14, 2026
13Strong evidenceTokyo, JapanHQ checked Sep 14, 202611-509 contacts →

Strong evidence

“Kéisén Associates, formerly Omori & Yaguchi, is a Tokyo-based Japanese intellectual property law firm with offices in Tokyo, Philadelphia and New York City.”

Source: RevenueBase Database · checked Sep 14, 2026
14Indirect evidenceMita, JapanHQ checked Sep 14, 20261-107 contacts →

Indirect evidence

“We are a group of professionals specializing in cross-border matters.”

Source: RevenueBase Database · checked Sep 14, 2026
15Strong evidence大阪市, JapanHQ checked Sep 14, 202611-505 contacts →

Strong evidence

“Innoventier is a group of Japanese law firm and patent office specializing in intellectual property laws and general corporate matters.”

Source: RevenueBase Database · checked Sep 14, 2026
16Indirect evidence横浜市西区みなとみらい2-2-1, JapanHQ checked Sep 14, 202611-504 contacts →

Indirect evidence

“In the heart of Minatomirai, Yokohama, Olive International Patent Office was established on October 1, 2003.”

Source: RevenueBase Database · checked Sep 14, 2026
17Indirect evidence阿倍野区, JapanHQ checked Sep 14, 2026201-5003 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 14, 2026
18Indirect evidenceChiyoda-ku, JapanHQ checked Sep 14, 202611-502 contacts →

Indirect evidence

“Tass Meister Patent Firm consists of patent attorneys and technical experts possessing advanced knowledge in their specialized areas.”

Source: RevenueBase Database · checked Sep 14, 2026
19Partial evidenceChuo-ku, JapanHQ checked Sep 14, 20261-102 contacts →

Partial evidence

“Akasaka International law, Patent & Accounting Office is commited to the highest standard of professional excellence in providing a complete package of legal, financial management…”

Source: RevenueBase Database · checked Sep 14, 2026
20Indirect evidence港区, JapanHQ checked Sep 14, 202611-501 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 14, 2026
21Strong evidenceTokyo, JapanHQ checked Sep 14, 20261-101 contacts →

Strong evidence

Intellectual Property Professionals We provide professional IP service to Japanese clients and foreign clients.”

Source: RevenueBase Database · checked Sep 14, 2026
22Indirect evidenceTokyo, JapanHQ checked Sep 14, 20261-101 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 14, 2026
23Indirect evidenceTaito-ku, JapanHQ checked Sep 14, 20261-101 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 14, 2026
24Indirect evidenceKamakura, JapanHQ checked Sep 14, 20261-101 contacts →

Indirect evidence

“Syndefense provides IP advisory and consulting services to companies, research institutions and individuals.”

Source: RevenueBase Database · checked Sep 14, 2026
25Indirect evidenceNerima-ku, JapanHQ checked Sep 14, 20261-101 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 14, 2026

Showing 25 of 86 intellectual property law firms based in Japan

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Intellectual property law firms based in Japan at a glance

As of Sep 14, 2026
22.1%Verified-email coverage
6.0Average contacts per company
11-50Median size (employees)
45.3%Largest-city concentration · Tokyo
Sep 14, 2026Page data refreshed

Companies by employee count

1-10
31
11-50
27
51-200
19
201-500
6
501-1,000
1

Email recency for this list is measured worldwide rather than for Japan, so it is reported there. Company counts and contact totals on this page are exact for Japan, over 86 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among intellectual property law firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Japan whose own description of what they do matches “intellectual property law firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names intellectual property law firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among intellectual property law firms, and records with no verified work email. Companies headquartered outside Japan are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 114 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 14, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Intellectual property law firms by metro

  • Intellectual property law firms in Tokyo39

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names intellectual property law firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many intellectual property law firms are there based in Japan?

RevenueBase identified 86 intellectual property law firms headquartered in Japan as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Shiga International Patent Office, headquartered in Tokyo, tops this list with the largest team on record.

Which city has the most intellectual property law firms?

Tokyo leads with 39 headquartered companies, followed by Jing (4) and Gifu City (2).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 114 verified decision-maker contacts tracked across these 86 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 14, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.