We are here to help you achieve your most ambitious goals

We’re Otani Accounting Office and we provide tax & accounting support for both domestic and foreign clients here in Japan. Our story began in 1983. Back then, we were a single tiny office providing our services to domestic clients only. Today, we are one of the leading accounting firms supporting multiple businesses around the globe. We love what we do and here you can learn why.



By combining our efforts and expertise with an array of experienced industry translators, we ensure that our clients receive efficient, handcrafted solutions that amplify their achievements and help them step up to the next level.



We know that starting a new business in a foreign country can be a challenge- that’s why we aim at providing a comfortable business environment for global clients.



We’ll dedicate all our knowledge, skills, and experience to build and maintain the bridge between foreign clients and the Japanese financial market- from startups to prospering companies, we are here to make success happen.

Our Brand Values

With our commitment to fair trade principles, expertise to drive transparency and the desire to embrace diversity, our values are the fuel for our clients as they work towards their goal.


We emphasize transparency and are committed to an open relationship with our clients. Through this approach, we aspire to build a long-lasting relationship constructed on a strong foundation of trust.


We are committed to creating an adaptable environment that embraces cultural differences and is always open to new experiences. An environment that promotes equity and respects diverse traditions, heritages, and experiences.

Fair Trade

Fairtrade is essential for international business. Securing the rights of foreign businesses and offering fair market prices - this is how we contribute to the sustainable development of Japan and foster its globalization process.

Our History

For Otani Tsuneyuki, the founder of the company, it all started in 1983 with a burning desire to establish his own tax and accounting firm.

Back then, Japan, being a very conventional country with almost no eagerness for new experiences, had a low number of foreign people living there. Providing services in English was unimaginable and had almost no viability.

Even with years going by and the number of foreigners increasing, the Otani Accounting Office was still solely focusing on Japanese clients until recently Tsuneyuki’s son, David, declared things had to change.

His idea was simple in concept – David wanted to serve foreigners by providing top-notch tax and accounting support. Consequently, the English Department was established in 2017 which was a turning point for the Otani Accounting Office.

Having achieved a new milestone, we could provide better support for foreign clients here in Japan, especially for those with cross-border interests. We were able to expand our vision and shape a new identity for the company.

From a single office established in 1983, we have grown to be one of the leading accounting firms in Japan which supports foreign businesses. Otani Accounting Office has found its niche, and we will continue to grow our business by helping you grow yours.

We can do that because we share an ambition to build a successful future with each and every client we work with. We are your trusted partner, with a commitment to your business that does not emanate from a desire for profits.

David Otani


Providing a comfortable business environment for global clients.

Here at Otani Accounting, we always wonder how far the notorious principle “When in Rome, do as Romans do” should extend to international business.

Ever since the company foundation, we’ve seen thousands of foreign businesspeople struggling with tax and accounting issues, let alone being able to read the forms or get professional advice in English.

We are not conventional. We aim to be different. OAO has made it its purpose to support foreigners to make them feel as if they’re practicing in their home country.

We exist in Japan. For foreigners. By foreigners.




By submitting, you agree to our   Privacy Policy  and   Terms of Use

Thank you for subscribing!

Check your inbox for monthly updates from OAO.

Thank you!
Your message has been successfully sent.

We well get back to you within 1 business day to discuss the details.