Based in Okinawa, Japan, Keystone Agency specializes in providing administrative support and translation services on a worldwide scale. We pride ourselves in our ability to bridge language gaps and connect businesses with the resources they need to succeed. Our 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 translation agency; we specialize in the effective communication of objectives in various modes, whether it is on a task, project, or an 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.

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


Keystone Agency provides administrative support and translation services in a variety of disciplines. 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 and offer 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.





Real Estate


Administrative Support

Our English/Japanese administrative support services revolutionize how businesses overcome language barriers. We utilize a cloud-based platform to streamline communication in addition to file and task management, ensuring no work is overlooked and we remain on schedule. We will liaise with Japanese or overseas customers, suppliers, consultants, law offices, accounting firms, and other relevant counterparties on your behalf.

 Service Scope
 Please contact us for further information or to inquire about customized plans that better suit your needs.


We have partnered with global players in the translation arena to provide quality work at the most competitive rates. By combining human translation with artificial intelligence, our services deliver precision with a beating heart.

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

Other Services


We provide verbal interpretation (verbal translation) services between English and Japanese remotely (telephone/video conference) or in person.


We provide transcription services for recorded audio, including interviews and meetings, in numerous languages. We can also provide captioning services for TV shows, motion pictures, and other visual media.


We have access to a wide selection of voice talents in various languages all over the world. We can also arrange a voice casting to find the right voice for your project.

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


Thank you for your interest in our services. Please expect a response from us within 12 hours, excluding weekends and Japanese holidays.* denotes

* denotes required field.

    Service Plan



    The best way to contact us is through our contact form. Please expect a response within 12 hours, excluding weekends and Japanese holidays.

    A source word/character refers to the word or character in the document you request to translate. This is what we use to prepare our estimates and account for the work we deliver.

    Yes, our prices include all applicable taxes.

    We accept PayPal and bank transfers.

    Payments of monthly service fees for administrative support services are due the following month, while payments for translation and other services are due in advance. Initial fees are due at the time of contract conclusion.

    Keystone Agency is a sole proprietorship.

    We handle all information obtained from clients with extreme care and under strict confidence. As such, we expect the same from our clients and include a provision for non-disclosure in our service agreement. All documents provided by clients through the course of our administrative support services are stored only on the cloud-based platform, from which our clients are free to remove them at any time. All documents provided by clients for our translation services are deleted after delivery. We also protect our website with SSL encryption for enhanced security in safeguarding any information transmitted through our website. For further details regarding our handling of confidentiality, please refer to our Privacy Policy.

    Please contact us, and we will assist you with the process.

    All rights to our deliverables are transferred to you at the time of your payment. As such, you are free to use them for any intended purpose.

    Our 100% satisfaction guarantee covers unlimited revisions to our deliverables at no additional charge to ensure you are fully satisfied with our work. Please note, however, that no refunds are administered under any circumstances.

    Administrative Support

    We apply your plan’s translation rate on all additional administrative work.

    Unused services, i.e., monthly administration, verbal translation, etc., on your plan are rolled over to the following month up to the contract term. There are no refunds administered for any unused services at the end of the contract term under any circumstances. Moreover, please note that services rendered using your unused services may take longer than usual to deliver, as each plan is designed to deliver the specified amount of work within a period of one month

    You are free to downgrade to a smaller service plan during the contract term, and the change will be reflected the following month of your request. Please note, however, that the ability to upgrade to a larger service plan will depend on our workload at the time and, consequently, may not be accommodated.

    The initiation fee is to cover expenses such as preliminary meetings up to the conclusion of our contract as well as other preparations to initiate our service. The initiation fee is non-refundable under any circumstances.

    The contract term is generally 12 months. However, we may exercise flexibility depending on the client’s needs. We would be glad to discuss this during our preliminary meeting.

    Our contracts are generally auto-renewal. However, we may exercise flexibility depending on the client’s needs. We would be glad to discuss this during our preliminary meeting.

    There is no penalty for early termination. You are, however, required to notify us of early termination at least 30 calendar days in advance. Without a 30-day notice, you will incur the subsequent month’s fee.


    You will receive a quote along with the estimated delivery time within 12 hours, excluding weekends and Japanese holidays, from the time of your request. We normally ask for at least 24 hours, excluding weekends and Japanese holidays, on Standard orders. Production priority is given to orders for Express Service.

    We can accommodate any order size. However, our quote starts at 200 source characters/words even if your order is smaller than that in order to cover production expenses.

    You can select “General” for the specialized field on the contact form, and your order will reach all translators who have passed the general screening to follow established quality standards. While your translation will be grammatically acceptable, there is no guarantee on the proper usage of technical terminology.

    We have access to an aggregated database of over 300,000 translators, covering more than 100 languages, through our partners who serve multinational corporations, governments, and various organizations all over the world. All translators are screened for professional language competency, quality compliance, and their knowledge of the fields in which they specialize if any. Your documents will be translated by one of the carefully selected translators, based on the order of availability, suitability, and competitiveness of offered rate, who will utilize a state-of-the-art CAT (computer-aided translation) software to ensure accuracy and consistency.

    Editors improve the composition of the translation for a natural reader experience in the specialized field of the target language. Translations can sometimes sound stiff, so we have editors to soften the edges without compromising the context. Our editors use enhancement tools for advanced editing, and they play an active role in our localization services. We include one editor in our Total Plan.

    Proofreaders are the final inspectors. They are the extra set of eyes to look for errors in the translation and correct them if any. We include a proofreader in all of our plans.

    We will count the characters for non-Latin languages, i.e., Chinese, Japanese, Korean, Hebrew, and Arabic, and the words for Latin languages, i.e., English, French, German, Italian, Portuguese, Spanish, etc., contained in the source document using Microsoft Word. We do not count spaces, numbers, and symbols towards our quote. You will be invoiced based on the figure indicated by Microsoft Word and our quoted unit price.

    Each quote is based on the available translator’s rate at the time of your request. Although every assignment goes to the translator with the most competitive rate in the specified field, there is no common rate for any language, as the translators set their own rates.

    All translators in the database have successfully passed the general knowledge test administered by our partners under stringent quality standards, which covers spelling, grammar, and composition for the requested language pair. Those selected for assignments in specialized fields have also passed the test for the respective field, which covers technical terminology for the requested language pair. Furthermore, all translators are aided by computer software equipped with translation memory that ensures consistency in the usage of terminology and quality in the overall work. With our Total Plan, the translation will then be submitted to an editor who has additionally been tested for editing competency and will use enhancement tools to improve the composition of the translation. Finally, all translations are submitted to a proofreader who will then review the translation before the translation is delivered. We operate like any other translation agency. The only difference is that we employ a more efficient process through the introduction of available technology. In the unlikely event that an error is discovered, we will not hesitate to correct it at no additional charge.

    A trial translation is a test mainly administered on large-scale projects for the purpose of ensuring that the translator satisfies the competency and quality standards required for the project. We offer free trial translations on materials of up to 200 characters/words. For trials exceeding 200 characters/words in translation, we apply our translation fee on the excess work.

    Yes. In this case, we would combine the percentages of each additional fee and apply it to the fee for the Standard Plan, e.g., [Express Plan % + Total Plan %] * [Standard Plan fee].

    You can send your documents to the email address provided on our quote or use a file transferring service, such as Google Drive and Dropbox, for large files.

    Localization, also known as L10N, is the process of adapting the language of a product to a specific country, culture, or region. This requires in-depth knowledge of the target audience that goes beyond translation. We offer localization services for mobile applications, websites, marketing materials, manuals, and many other products.

    Other Services

    We conduct prior consultations for all inquiries to ensure proper understanding of the topic and to discuss effective ways to communicate the material to the target audience. Prior consultations are mandatory for all verbal translation/interpretation services we offer and can be conducted via telephone/video conference.

    We need enough time for prior consultation to understand the nature of the verbal translation/interpretation services requested. Depending on the subject and available materials, our prior consultation can take as little as one hour.

    Prior consultations are included in our fees for translation services of at least three hours. We assess a consultation fee of JPY 3,900 for verbal translation/interpretation services of less than three hours to cover administrative expenses.

    We invite a number of voice talents based on the criteria you specify, e.g., age, gender, tone, language, etc., to participate in an audition for your selection. Voice casting is an effective way for you to find the right voice to convey your message.

    We provide timestamps and timecoding on transcriptions for an additional fee of 25%.

    Yes, we can transcribe files with multiple speakers at no additional charge for up to three speakers. Each additional speaker thereafter is subject to an additional fee of 10%. All speakers are identified consistently throughout the transcript.

    We can include filler words, a service which is commonly referred to as verbatim transcription, for an additional fee of 25%. This will include all filler words, such as “um,” “hmm,” [laughs], and [clears throat].