“ Plan. Launch. Manage. Grow. ”


Based in Okinawa City, Okinawa, Japan, Keystone Agency LLC specializes in providing business administrative support as well as translation and interpretation services to private-sector businesses and US military contractors. We pride ourselves on our ability to bridge language gaps and connect businesses with the resources they need to succeed. Our experience and dedicated services give startups as well as established enterprises the confidence they need to capitalize on the endless potential of today’s unique marketplace.

Keystone Agency is more than a conventional translation agency; we specialize in the effective communication of objectives in various modes, whether it is on a task, project, or ongoing basis. We utilize a wide range of IT solutions to maximize productivity while minimizing cost, which allows us to deliver our services at the most competitive rates in the market—efficiency is the keystone of our operation.

Executive Profiles

Ritchi Kumagai
Member of the American Chamber of Commerce in Okinawa
Member of the Japan Association of Translators

Ritchi specializes in domestic and cross-border business transactions in a wide range of industries, from construction and finance to IT and marketing. As a professional translator with over 10 years of experience, he has served dynamic roles in an array of business settings, assisting overseas enterprises entering the Japanese market as well as Japanese companies expanding overseas. Ritchi founded Keystone Agency in 2014.

Joe William Johnson
Member of the American Chamber of Commerce in Okinawa
Member of the Lion's Club

Joe has an extensive background in business management, having served on the board of the largest staffing agency in Okinawa for several years. He possesses a proven track record of preparing the necessary documentation for bidding and managing contracts on US military installations across Japan. He is bilingual, fluent in both English and Japanese, and has been serving as the advisor of Keystone Agency since 2022.


Helping to Find Solutions for Language Barriers

Keystone Agency provides administrative support, translation and interpretation, and US military contracting services. Think of us as an extension of your team, specifically, for facilitating communication between English and Japanese. We possess well-grounded expertise in both languages and cultures, offering services tailored to individuals and organizations that hold the necessary command in a given area of business but require assistance in conquering language barriers. Please scroll down to find out more about our services.


US Military





Business Administrative Support

Total Support Connecting Businesses Through Language

Our English/Japanese business administrative support services revolutionize business solutions in how businesses overcome language barriers. We utilize solutions to streamline communication while managing files and tasks to ensure no work is overlooked and we remain on schedule. We will liaise with Japanese or overseas customers, suppliers, consultants, government agencies, and other relevant counterparties on your behalf. Please contact us for a free consultation.

Service Scope

If you are looking for a business partner in Japan, we have the team to assist you. From business registration and licensing to accounting and labor, we can connect you with all the resources you need to succeed.
 Please contact us for further information or to inquire about customized plans that better suit your needs.

Translation & Interpretation

From Small Personal Inquiries to Large Corporate Projects

We are partnered with global suppliers in the arena of language solutions to provide quality work at the most competitive rates. By combining human translation with artificial intelligence, our services deliver precision with a beating heart. We also provide interpretation (verbal translation) services between English and Japanese, which may be arranged in person or remotely through telephone and video conferencing platforms. Please contact us for a free consultation.

Service Scope

 Please contact us for further information regarding our translation services or to request a free quote.

US Military Contracting

Business with the US Military Made a Breeze

We provide assistance with registering as a vendor and preparing solicitation packages to navigate and secure US government military contracts from start to finish. We will advise on project requirements, bidding, execution, inspection, and document processing to serve as our clients’ one-stop source for understanding and communicating with the US government on various military projects. Discover why our clients choose us. Please contact us for a free consultation.

Service Scope

 Please contact us for further information regarding our services or to request a free quote.


Keystone Agency LLC

Thank you for your interest in our services. Please expect a response from us within 1-2 business days, excluding weekends and Japanese holidays.

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    Service Plan