*Translated by Google Translate

Introduction

"How would you feel if you were told that you were a 'stranger' just because you went abroad with your partner, with whom you live as a family?"

We are a Japanese-French couple, Rei, a Japanese actor, and Coralie, a French film director, who met at drama school in the UK. We got married in France in 2018 and now live in France as partners both in our personal and professional lives, working in film production.

However, same-sex marriage is still not recognized in Japan, and even though we are officially married overseas, our relationship is not reflected in the family register in Japan. Even if there is a possibility of relief through individual judicial decisions or administrative interpretations, there is always the risk that we will not be treated as spouses. This situation causes serious anxiety about our future and the formation of a family. With the natural desire in our hearts to be recognized as a family in Japan, we decided to take legal action.

I also learned that just because the Supreme Court has ruled that "not allowing same-sex couples to marry is unconstitutional" does not mean that same-sex marriage registrations will be accepted at city hall. This lawsuit is a procedure aimed at "accepting marriage registrations at city hall." We are working with the hope that "we will be recognized as a family in Japan as soon as possible."

Contents of the trial

The "Freedom of Marriage for All" Lawsuit, which began in 2019, has won a court ruling that "not allowing same-sex couples to marry is unconstitutional" within the framework of a lawsuit seeking compensation from the state. It is expected (and we have high hopes) that the Supreme Court will also rule it unconstitutional (as of December 2025).

However, just because the Supreme Court ruled that "it is unconstitutional for same-sex couples not to be able to marry" does not mean that the two can become legally "spouses."

When the Supreme Court rules that "it is unconstitutional for same-sex couples not to be able to marry," the rule is that "the Diet must correct the system that has been deemed unconstitutional," but it is unclear when the system will actually be changed and put into practice. In the meantime, same-sex couples' marriage registrations will not be accepted, and they will simply have to wait. This lawsuit was launched out of a sense of crisis about this situation.

The plaintiffs, Watanabe Prosper Rei and Coralie, filed a marriage notification (Article 41 of the Family Register Act) with the mayor of Amagasaki City, Hyogo Prefecture, where Rei has her registered domicile, regarding their marriage in France. However, the mayor did not accept the notification, stating that "in Japan, the Constitution and Civil Code presuppose that marriage is between a man and a woman, and since there is no provision for same-sex marriage, the marriage is deemed invalid."

In this lawsuit, we are seeking to have our marriage registration accepted immediately as a same-sex couple, without waiting for the Diet to amend the law. If we win this lawsuit, we will be able to become a married couple in Japan right away.

The petitioner's thoughts

The reason why we decided to start this lawsuit was because we did not want to give up on the future where we would be recognized as a "family" in Rei's home country, Japan.

We met at drama school in the UK, were attracted to each other's work and outlook on life, and married in France in 2018. We are currently working together on a film in France. Even in the midst of this trial, we released a short film, "Kotowari 断り," which was also released in Japan. It tells the story of a Japanese woman's struggle to obtain a residence permit so that she can live in France with her beloved French same-sex partner, and is based on our own experiences.

In France, we are able to live as a married couple protected by the law, and I'm sure that will continue to be the case in the future.

However, when we returned to Japan together for a short visit, we mentioned in casual conversation that we got married in France, and people thought we were joking and laughed. We realised that in Japan, where same-sex marriage is not a legal system, our relationship is beyond people's imagination.

We are thinking about having children in the future, but in Japan we are not a "family" but, legally, "strangers." The current situation leaves us feeling very anxious, with no guarantee that we will be protected if something were to happen. There are many international queer couples in similar situations. We want these couples to have the option of "living in Japan." And so that the next generation can proudly say, "Japan is my country, too." We wanted to take that first step in this lawsuit.

Reasons why you should accept their marriage registration

1. The Civil Code does not prohibit same-sex marriage

The Civil Code does not state that same-sex couples cannot marry.

It is true that the current Civil Code contains provisions that may be read as not recognizing same-sex marriage, such as terms like "husband and wife," "husband," and "wife." However, these provisions concern the effects of marriage, that is, what happens "after" a marriage is established, and are not rules that determine whether a marriage is valid. These provisions have no bearing on whether a same-sex couple's marriage is valid; after a marriage is established, it is sufficient to consider whether these provisions apply to the "couple."

Based on this, we have conducted a "full check" of all provisions of the Civil Code relating to family matters, such as marriage, divorce, parent-child (biological parent-child and adoption), and inheritance, and have confirmed that none of these post-marriage rules contradict or are compatible with the existence of same-sex marital relationships.

2. There is no consistent basis for the civil law theory that says same-sex marriage is not allowed

Until now, civil law researchers have taken it for granted that "the Civil Code does not recognize same-sex marriage." However, if we look at the "basis" for this, we see that as the eras have passed from Meiji to Taisho to Showa to Heisei, the "basis for saying that the Civil Code does not recognize same-sex marriage" has changed one after another, and there is no consistent basis. The view that "the Civil Code does not recognize same-sex marriage" is by no means a firm interpretation of the Civil Code.

3. The Civil Code should be interpreted in light of the Constitution

Because the Constitution is a higher law than the Civil Code, the Civil Code must be interpreted based on the constitutional argument that "it is unconstitutional not to allow same-sex couples to marry." Five of the six high court rulings in the "Freedom of Marriage for All Lawsuit" have ruled that "not recognizing same-sex couples' marriage is unconstitutional." In particular, the Sapporo High Court and the Fukuoka High Court have ruled that "same-sex marriage is guaranteed by the Constitution." Since the Civil Code does not contain any provisions prohibiting same-sex marriage, same-sex marriage must be recognized under the Civil Code, given that not allowing same-sex couples to marry is unconstitutional.

As a result of interpreting the current Civil Code in this way, there is no longer any reason for the current non-acceptance, so the notification should be accepted without waiting for a legislative solution.

If the legislative inaction of the Civil Code and Family Registration Act, which stipulate nothing about same-sex marriage, is a violation of the Constitution, then their marriage will not be recognized until the Diet amends the Civil Code. But is that really the right thing to do? We believe that the goal is for their marriage to be recognized.

Therefore, if the absence of a civil law that recognizes same-sex marriage is unconstitutional, the courts should interpret the civil law flexibly to recognize the marriage of two people, rather than waiting for an amendment by the Diet. For example, if two people who wish to marry meet all the requirements for marriage except for being "of the opposite sex," the courts should supplement and interpret the civil law to recognize the marriage of two people under the civil law (constitutional supplementary (expanded) interpretation).

Even if the court rules that their marriage is unconstitutional, if their marriage is not recognized, their wishes will not be fulfilled. We are asking the court to recognize their marriage.

▼Claim about couples in a marriage in a country where same-sex marriage is already legal

4. Theory of Recognition of Personal Status (Arguments in the Field of Private International Law)

We advocate the "recognition of status relationships" theory in private international law (the theory that status relationships recognized in other countries should be recognized as much as possible). Since the two are legitimate "spouses" in France and meet the requirements for marriage in Japan except for the opposite-sex requirement, their marriage recognized in France should also be recognized in Japan.

5. Application of Article 79-2 of the Domestic Relations Proceedings Act (Arguments in the Field of Private International Law)

In the field of private international law, he argues that "public decisions of foreign countries should be recognized in family courts."

social significance

I think it all comes down to realizing same-sex marriage as soon as possible.

The purpose of this trial is for the two to actually become a couple in Japan.

In order for two people to become husband and wife, their marriage registration must actually be accepted.

Therefore, they chose to take legal action (family court proceedings) and asked the mayor to order the couple to accept their marriage registration.

If the court recognizes marriage for same-sex couples based on its interpretation of the Civil Code, Family Registration Act, and private international law, then same-sex marriage will be recognized in Japan from that day on. If the Supreme Court upholds this decision, it will be a ray of hope for the many same-sex couples who have been waiting for a society that allows same-sex marriage.

The defense team's thoughts

Our legal team took on this case in order to fulfill the couple's wish to become a married couple in Japan. Even if we go to court and receive a ruling that the marriage is unconstitutional, we will not have achieved our goal unless their marriage is recognized.

If we take the interpretation that the Civil Code does not recognize same-sex marriage, then even if not allowing same-sex marriage is unconstitutional, their marriage will not be recognized unless the Civil Code is amended. There are various opinions regarding the introduction of same-sex marriage, and even if the courts rule it unconstitutional, there is a good chance that the Civil Code will not be amended immediately.

In such a situation, isn't it the mission of the court, which is endowed with the power to review constitutionality and whose role is to protect the rights of minorities, to provide relief to these two people who cannot be considered part of the majority?

We are working on this lawsuit with the hope of increasing the option of judicial resolution in addition to legislative resolution.

▲ In Komagane City, Nagano Prefecture, where Professor Nobuyoshi Ashibe, a leading figure in constitutional law, was born and raised.

Introduction of the lawyer in charge

Mayuko Miyai (Nagano Bar Association) : Head of the defense team. She is responsible for checking all provisions of the Civil Code to see if same-sex marriage is permitted, and examining civil law theories from the Meiji era to the present day. She is always interested in family law cases.

Masahiro Kaneda (Nagano Bar Association) : Graduated from the Department of Philosophy. In the "Azuminosato Special Nursing Home Case," he won a not guilty verdict at the Tokyo High Court. He has always been interested in constitutional theory.

Shuichi Yoshida (Nagano Bar Association) : Matsumoto Branch of Adire Law Office. Mainly in charge of public relations and external relations.

Hiroki Oikawa (Nagano Bar Association) : Secretary General. Lead defense attorney for the retrial defense team in the Azusa Express theft false accusation case.

Takeru Ito (Toyama Bar Association) : Constitutional law specialist. Has a track record of winning a Supreme Court reversal in a lawsuit to lower the standard of public assistance. Has written numerous books and articles on the constitution.