2025.09.04

2024(Ju)239

Minshu Vol. 79, No. 6

(Civil Case) Judgment concerning whether an action to seek a declaratory judgment of the invalidity of an agreement specifying the manner of sharing living expenses as a married couple is a lawful action

Case seeking a declaratory judgment of the invalidity of an agreement on living expenses of a married couple

Judgment of the First Petty Bench, quashed and decided by the Supreme Court

Tokyo High Court, Judgment of September 27, 2023

An action to seek a declaratory judgment of the invalidity of an agreement specifying the manner of sharing living expenses as a married couple is not in accordance with the law due to the lack of interest in seeking a declaratory judgment.

Article 760 of the Civil Code; Article 134-2 of the Code of Civil Procedure; Article 39 and Appended Table 2, row (2) of the Domestic Relations Case Procedure Act

1. The judgment in prior instance is quashed. 2. The appeal filed by the appellee of final appeal to the court of second instance is dismissed. 3. The costs of the appeal to the court of second instance and the costs of the final appeal shall be borne by the appellee of final appeal.

Concerning the reasons for a petition for acceptance of final appeal stated by the counsel for final appeal, IMAZU Hiromu 1. The outline of the facts legally determined by the court of prior instance is as follows. (1) The appellant of final appeal and the appellee of final appeal married but later started to live separately, and in January 2017, they reached an agreement to the effect that the appellant would pay the appellee 160,000 yen per month from that month as living expenses (referred to below as the "Agreement"). Since then, until August 2022, the appellant paid the appellee that amount each month. (2) In November 2020, the appellee filed a petition against the appellant with the Tachikawa Branch of the Tokyo Family Court to seek a ruling regarding the sharing of living expenses. The Tachikawa Branch determined that the Agreement had been reached based on the appellant's annual income that was lower than the actual amount at that time, and as this constitutes a factor due to which the amount of living expenses to be borne by the appellant based on the Agreement should be changed, the amount to be borne by the appellant since November 2020, when the abovementioned petition was filed, should be changed. In conclusion, in September 2022, the Tachikawa Branch made a ruling to order the appellant to pay the difference between the amount to be borne by the appellant after the change and the amount already paid, as well as 290,000 yen per month from September 2022 onward. 2. In this case, the appellee sues the appellant to seek a court's declaratory judgment of the invalidity of the Agreement, alleging that there was a mistake regarding the appellant's annual income. The appellee argues that the appellee has interest in seeking a declaratory judgment by filing this action because regarding the living expenses incurred during the period extending from after the Agreement was reached until the petition was filed, the appellee is planning to file another petition for a ruling to grant an amount to be borne by the appellant that is larger than the amount specified in the Agreement, and that obtaining a judgment that declares the invalidity of the Agreement is a prerequisite for that planned petition. 3. The court of prior instance held that this action is an action for a declaratory judgment to seek a determination on the existence or non-existence of the Agreement, a legal relationship established in the past, and by determining as summarized below, it reversed the judgment in first instance that had dismissed this action as one not in accordance with the law, and remanded the case to the court of first instance. If an agreement specifying the manner of sharing living expenses as a married couple (referred to below as an "agreement on living expenses") has been validly established between a husband and wife, the subsequent manner of sharing living expenses would be based on that agreement on living expenses. A family court may not make a ruling regarding the sharing of living expenses unless any change in circumstances is found to have occurred, and even if any change in circumstances is found to have occurred, with regard to the living expenses incurred after the time when the agreement on living expenses was established until the time when the change in circumstances is found to have occurred, a family court may not make a ruling to order the obligor to pay an amount that is different from the amount to be borne by the obligor based on the agreement on living expenses. Accordingly, if a husband or wife is to initiate proceedings to seek a ruling regarding the sharing of living expenses to adopt a manner of sharing that is different from the one specified in the agreement on living expenses, determining the invalidity of the agreement on living expenses through a civil lawsuit is the most appropriate and necessary process for reaching a direct and fundamental solution to the dispute between the parties. Therefore, an action to seek a declaratory judgment of the invalidity of an agreement on living expenses established between a husband and wife is a lawful action based on the interest in seeking a declaratory judgment. 4. However, the abovementioned determination by the court of prior instance cannot be upheld, for the following reasons. Even with regard to a legal relationship established in the past, if determining that relationship is found to be the most appropriate and necessary process for reaching a direct and fundamental solution to the present legal dispute, an action to seek a declaratory judgment on the existence or non-existence of the relationship is acceptable as an action based on the interest in seeking a declaratory judgment (see 1969 (O) 719, the judgment of the First Petty Bench of the Supreme Court of November 9, 1972, Minshu Vol. 26, No. 9, at 1513; 1991 (O) 252, the judgment of the Third Petty Bench of the Supreme Court of March 7, 1995, Minshu Vol. 49, No. 3, at 893). In this respect, while the obligation to share living expenses as a married couple is for ensuring the economic security in the couple's livelihood, it could be affected by factors such as the couple's income and living situation that may change from time to time. In light of this, the manner of sharing of living expenses would not remain fixed even after an agreement on living expenses is established, but a new manner of sharing could be adopted at the right time. For this reason, if proceedings to seek a ruling regarding the sharing of living expenses are initiated, and the parties dispute over whether the agreement on living expenses has been validly established and either or both of them demand that a manner of sharing living expenses that is different from the one specified in the agreement be adopted, a family court is to make a ruling to decide a new manner of sharing living expenses by taking into consideration not only the existence or non-existence, validity, and details of the agreement on living expenses, but also all the other circumstances such as the couple's income and living situation, and also by examining the amount of living expenses currently borne by the obligor, the time of commencement of its payment, and other matters. Then, even if the validity of an agreement on living expenses has not yet been determined in a civil lawsuit, this would not preclude a family court from adopting a manner of sharing that is different from the one specified in the agreement on living expenses (if, in such case, either party demands that an amount to be borne by the obligor that is different from the amount specified in the agreement on living expenses be adopted despite the valid establishment of the agreement, a family court may make a ruling to newly adopt the amount that is equal to the amount to be borne specified in the agreement instead of dismissing the party's petition as one not in accordance with the law, even when reaching a conclusion, as a result of the proceedings, that there are no circumstances requiring the revision of the amount to be borne by the obligor based on the agreement). In addition, if it is made allowable to obtain a declaration by the court in a civil action only with regard to whether an agreement on living expenses has been validly established although the manner of sharing living expenses may not be decided in a civil action, a family court would have to wait for the outcome of the civil action, which could cause a delay in deciding the manner of sharing living expenses that must be decided by a family court's ruling in a timely manner in order to ensure the economic security in the couple's livelihood. Therefore, it cannot be said that it is necessary to allow a husband or wife to dispute about the validity of an agreement on living expenses by separately filing an action for a declaratory judgment, nor can it be said that it is appropriate to allow this. According to the above, it cannot be said that seeking a declaratory judgment in a civil action with regard to whether an agreement on living expenses of a married couple has been validly established is the most appropriate and necessary process for reaching a direct and fundamental solution to the dispute concerning the manner of sharing living expenses. Consequently, an action filed by a husband or wife to seek a declaratory judgment of the invalidity of an agreement on living expenses of a married couple should be judged to be an action that is not in accordance with the law due to the lack of interest in seeking a declaratory judgment. 5. The determination by the court of prior instance that is contrary to the above contains a violation of law or regulation that has clearly influenced the judgment. The counsel's arguments are well-grounded as they argue this point, and the judgment in prior instance should inevitably be quashed. According to the explanation given above, the judgment in first instance that dismissed this action as one that is not in accordance with the law can be upheld, and therefore the appeal filed by the appellee to the court of second instance should be dismissed. For the reasons stated above, the Court unanimously decides as set forth in the main text of the judgment.

Justice MIYAGAWA Mitsuko Justice YASUNAMI Ryosuke Justice OKA Masaaki Justice SAKAI Toru Justice NAKAMURA Makoto