About Us

aboutusOur Mission

With more than thirty years of professional experience, we assist our clients in each and every stage of their continuous growth. We develop efficient and flexible solutions to support them in achieving their business goals. That's our mission.

Quality Services

We provide the international business community both in the U.S.A. and Japan with quality bilingual (Japanese/English) accounting, tax, payroll and advisory services to over 100 domestic and international clients. Our clients range from a number of industries from large worldwide corporations and SEC listed US companies to local import/export retailers.

Company Profile

Harnessing our more than 30 years of combined experience, we established Oshima Saito LLP in January 2001 with the desire to provide our customers with efficient, customized, and goal-oriented service.

With headquarters in New York City, and branch offices in Los Angeles and in Shibuya, Tokyo (opened January 2001 and October 2008, respectively), we are able to serve our clieants globally.

Our staff is made up of highly experienced American Certified Public Accountants and Japanese Certified Public Accountants with expertise in matters of banking, law and audits. We offer expert knowledge and guidance for a range of accounting needs, including corporate finance management, personal investments, and estate,inheritance and gift tax.

We have provided advisory services, and met the accounting and tax needs of a wide range of clients from private enterprises and small businesses, to international corporations. Our target clients do business in both U.S.A. and Japan, and our staff is able to assist clients in both Japanese and English.

The best feature of our firm is that all three of our international offices will work together to optimally serve you. If you are in Tokyo, with a branch in New York, or vice versa, we can facilitate easy communication in real time without the inconvenience of time differences or language barriers.


Koki Saito, Partner and CPA in U.S.A. & Japan



Certified Public Accountant in the U.S.A. and Japan. Graduate of Otaru University of Commerce, Major in Commerce and Economics. Entered Century Audit Corporation (now known as Ernst & Young Shin Nihon LLC), one of the “Big Four” accounting firms in Japan. In 1992, he was assigned to the firm’s Los Angeles office. While in the U.S., he studied American accounting at the University of Southern Caifornia, Los Angeles. He then moved on to KPMG in New York, where he worked as Senior Manager in the audit department. In January 2001, he established Koki Saito & Co. in New York and Los Angeles. On January 1st 2003, his firm merged with Oshima Accounting Offices. He is now a partner of Saito LLP (Saito Group).

  • 1991: Became a Certified Public Accountant in Japan
  • 1995: Became a Certified Public Accountant in the state of California
  • 1996: Became a Certified Public Accountant in the state of New York

Naomi Wada, Manager

  • U.S. Public Accountant
  • Manager in Tokyo office
  • BA in History and Science, Tokyo Women's Christian University

Worked in government-related banking and finance. After 14 years in the U.S.A., she specializes in tax management services, filing and writing statements. She is the Manger of Saito LLP (Saito Group).




  • 2007: Became a Certified Public Accountant in the state of New Hampshire

Takeshi Ozeki, Manager

  • Certified Public Accountant in California ( certified in 2006. )
  • Manager in New York office
  • BA in Economics, Osaka Prefecture University ( Japan )

He has been with Saito LLP since he moved to New York in 2002, aiming working as a professional accountant in U.S. He was inspired by the experience working with US CPA's while he was with one of the major Japanese corporations as a member of NYSE IPO project team. He specializes in financial statements audit, taxation and other accounting & tax related services.