Date of the judgment
1998.02.26
Case number
1994 (O) No. 1900
Reporter
Minshu Vol. 52, No. 1, at 255
Title
Judgment upon the case concerning the joint use of a real estate in co-ownership by a common-law couple and the assumption of an agreement of single use of the said property by one party of the said couple in the event of the death of the other party.
Case name
Case to seek the return of unjust enrichment.
Result
Judgment of the First Petty Bench, quashed and remanded
Court of the Second Instance
Fukuoka High Court, Judgment of June 30, 1994
Summary of the judgment
When a common-law couple has been jointly using real estate in co-ownership for the purpose of residing or operating a joint enterprise, as long as there is no particular circumstances, it is assumed that an agreement has been reached among the said couple on the single use of the said real estate by one party of the couple in the event of the death of the other party.
References
Article 249 and Article 703 of the Civil Code, Part IV, Chapter 2, Section 1 of the Civil Code [Formation of Marriage], Article 247 of the Code of Civil Procedure

Article 249 of the Civil Code
Each co-owner may use the entire property in co-ownership in proportion to his/her share.

Article 703 of the Civil Code
A person who has benefited from the property or labor of others without legal cause and has thereby caused loss to others shall assume an obligation to return that benefit, to the extent the benefit exists.

Article 247 of the Code of Civil Procedure
In rendering a judgment, the court shall, considering the entire import of the oral argument and the result of the examination of evidence, and based upon its freely determined conviction, decide whether or not the allegations of fact are true.
Main text of the judgment
The judgment of prior instance shall be quashed to the extent of the parts where the appellant has failed in the action.
This case shall be remanded to Fukuoka High Court with respect to the parts prescribed in the preceding paragraph.
Reasons
Regarding the reasons for final appeal argued by YASUDA Yukuo, counsel of the appellant,

1. According to the facts decided and the record of the court of second instance, the outline of the case is as follows. (1) The appellant and A were a common-law couple from 1959 and jointly operated an enterprise manufacturing and distributing boards used for teaching the playing of instruments, and jointly possessed the real estate in question for the purpose of residing and operating the enterprise mentioned above. (2) A died in 1982 and rights of A to the real estate in question were acquired by the appellee, child of A, as a result of inheritance. (3) The appellant has been singularly using the real estate in question for the purpose of residing and operating the enterprise mentioned above after the death of A. (4) Between the appellant and the appellee, a lawsuit has been pending regarding the ownership of the real estate in question, in which the appellee claimed that the real estate in question was in single ownership of A and the appellant claimed that the real estate in question was in co-ownership with A. For the said lawsuit, it was found that the real estate in question was property in co-ownership of the appellant and A and a judgment became final and binding by which it was confirmed that the appellant owned a one-half share.

2. This is a case in which the appellee seeks from the appellant the return of unjust enrichment claiming that the appellant is benefiting without legal cause the amount equivalent to one half of the rent for the real estate in question by singularly using the real estate in question. The court of second instance recognized an establishment of unjust enrichment in regard to the profit obtained by using the real estate in question in excess of the share of the appellant and accepted part of the claim by the appellee.

3. However, the said finding of the court of second instance cannot be affirmed for the following reasons.
Co-owners can make use of a property in co-ownership only in proportion to the shares of each person and do not have title by definition to singularly use the property in co-ownership without consulting other co-owners. However, in a case in which it is decided by mutual agreement among co-owners that one of the co-owners singularly use the property in co-ownership, unless and until the said agreement is amended or co-ownership is cancelled, it is understood that the co-owner for which single use has been approved as a result of the said agreement may singularly use the property in co-ownership and assumes no obligation against other co-owners to return unjust enrichment obtained by the said. Furthermore, in a case in which a common-law couple is using the real estate in co-ownership for the purpose of residing or operating a joint enterprise, as long as there is no particular circumstances, it is proper to assume that an agreement has been reached among the said couple on the single use of the said real estate by one party of the couple in the event of the death of the other party. Because, taking into accounts the said relationship among the couple as well as the status of use of the real estate in co-ownership, it corresponds to the normal intention of both persons to grant a living spouse in common-law marriage the exclusive right to use the real estate in co-ownership and to maintain the use of the real estate without charge with the same purpose and mode as the prior and existing purpose and mode in the event of the death of one party.
Considering the present case in the light of this, because the appellant and A who had a common-law marriage were jointly using the real estate in question in co-ownership for the purpose of residing and operating a joint enterprise, as long as there is no particular circumstances, it is proper to assume that an agreement has been reached among the said couple on the single use of the said real estate by one party of the couple in the event of the death of the other party. Considering the above, it is clear that the determination of the court of second instance for which proceedings regarding the existence or nonexistence of the said particular circumstances were not fully conducted and where it was found that an unjust enrichment had been established is illegal in that construction and application of laws and regulations are mistaken, and it is further clear that the said illegality shall have an effect on finalizing the judgment. The argument has sufficient ground for this purpose and the judgment of prior instance shall inevitably be quashed in regard to the parts where the appellant has lost. In addition, the case shall be remanded to the court of second instance in regard to the said parts in order to have further proceedings conducted regarding the existence or nonexistence of the said particular circumstances.

For the reasons mentioned above, the Court decides as stated in the main text of the judgment, with the decision being reached unanimously by all the Justices.
Presiding Judge
Justice ONO Motoo
Justice ENDO Mitsuo
Justice IJIMA Kazutomo
Justice FUJII Masao
Justice ODE Takao
(This translation is provisional and subject to revision.)
(* Translated by Judicial Research Foundation)