Welcome to setagaya international law office

An English-speaking law firm assisting foreigners living in Japan

Extensive experience in international legal disputes involving foreign nationals


International Family Law Conflicts

International divorce, custody and visitation disputes, hague convention cases, spousal and child support, property distribution, etc.


Labor Disputes

Unlawful dismissal, general labor matters, employee benefits, compensation, etc.


Criminal Cases

Foreigners being arrested/indicted in Japan


Immigration Law

Change/Renewal of visa status, permanent residency

Fluent and smooth communication in English


Effective communication

When involved in a legal dispute, it is very important to have a lawyer who can guide you through the process without any language barriers.


Strategy development

We take the time to carefully listen to our clients so we can fully understand what their concerns are. Then we take the time to explain the necessary legal process and clarify what we can achieve.


Constant contact

We also value staying in frequent communication and involving clients in every decision and every step of the way.

Reasonable fee structures designed to fit your needs

We take special care to avoid any situation which might cause our clients to struggle financially during an already stressful situation.

Depending on our clients’ financial situations and complexity of their cases, we aim to offer an affordable and personalized payment schedule for any scenario.

We're happy to look into your situation. Contact us for a free 30 minute consultation

Seiya Sato, Founder

Prior to founding Setagaya International Law Office, Seiya Sato acquired his Bachelor of Law (LL.B.) in 2011 from Rikkyo University. 

In 2013, he got his J.D. from Keio University Law School, before passing the bar examination. 

In 2014, he became a member of the Tokyo Bar Association.

From 2014 until 2020, he worked at Masayuki Honda International Law Office. From 2016 until 2018, he was a member of the Tokyo Bar Association Committee on the Protection of Foreigners’ Human Rights.

Seiya Sato is featured on the US, Canada and UK Embassy’s lists of English-speaking lawyers in Japan. 

He is also a registered lawyer of Japan Federation of Bar Associations’ Lawyer Referral Service for Hague Convention Cases.

Setagaya International Law Office

Frequently Asked Questions

I live outside of Tokyo/Kanto area. Can you still represent me?

Yes, of course. Meetings with clients can be done online and normally we can request the court to hold mediation/court hearings via telephone if the court is outside of Kanto area. When there is a hearing that we need to attend physically, we may ask you to pay some actual expenses such as transportation fees.

Can you schedule a consultation even on weekends?

Depending on urgency of your case, we can accomodate consultations even on weekends. Land line is only available on weekdays. But you can reach out to us via email, Line, WhatsApp, or Skype. Please click here.

What if the free 30 minute consultation is not long enough?

If we think it’s necessary to discuss your case more after having a 30 minute free consultation, we can then set up a 30 minute consultation which will cost 5,000 yen plus tax (or a 1 hour consultation, which will cost 10,000 yen plus tax).

I’ve already hired a lawyer. Can I still have a consult with Setagaya International Law Office?

Yes, you can. But if we think that the current lawyer is doing the right job, we may have to decline to represent your case.

Can anybody find out that I had a consultation at your firm?

No, any information regarding your consultation will not be disclosed to anyone due to our duty of confidentiality.

How can I make the payment for lawyer’s fee?

We accept cash, wire transfer, or credit card (via PayPal).


"I came to Sato-san with a difficult case: my ex-partner, to whom I had never been married, was trying to cut me out of my one year old daughter’s life. She clearly believed she would succeed, and a review of common outcomes for unmarried fathers, especially those of very young children, would support this view. However, meticulous work by Sato-san to document my attempts to be involved in my daughter’s upbringing, as well as his detailed knowledge of court procedures and personalities, allowed us to secure a court judgement that secured me weekly overnight stays with my daughter. Sato-san is not just a lawyer who speaks English, he is a father himself and will be a strong ally throughout what can be a long and tiring process. I have no reservation in recommending him for what will probably be one of the most important episodes of your life."
Custody, Access, & Parenting
"Seiya Sato was everything I had hoped for in a lawyer when I hired him in 2018 to assist me with my divorce proceedings in Japan. As an American in Japan, for me he had a terrific combination of legal experience and knowledge, understanding of international considerations and great communication skills. He saw me through a very difficult time and I was very satisfied with the results. I would highly recommend him."
International Divorce & Separation
"I can say from my heart that I was extremely lucky to find Sato san and that he accepted my case in a very tough child visitation case where the mother tried to block access to my son, this is unfortunately a common problem in Japan when parents separate. The outcome was unusually good and successful based on Japanese family court standards. I gained frequent and regular visitation to my son as stipulated by the court. Without Sato san’s expertise, positive energy, attention to the big picture and all the detailed proceedings, my chances would have been zero. His human touch helped manage me in a difficult emotional situation, as well as gained a good relationship with court members and our opposite lawyer and family, and my son. As a foreigner I think it is essential to not only have a lawyer, but make sure to have one of the very best. Sato san is for sure one of the best."
Custody, Access, & Parenting
Contact info

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Let's talk about your case. We look forward to hearing from you.

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ASTILE Sangenjaya II−502, 3-16-3, Taishido, Setagaya-ku, Tokyo, 154-0004, Japan

OFFICE hours

8:30 - 18:00 Mon - Fri