Whether a new claim for return of unjust enrichment may be filed by a landowner in case where there are circumstances, such as that the rent is not reasonable after a favorable judgment becomes final and conclusive after filing a lawsuit for future performance seeking the return of unjust enrichment equivalent to the rent.

[Majority Opinion]

In a case where a suit is filed against a land owner without any legal ground for future performance against a person who occupies the land, and the possessor claims the return of unjust enrichment equivalent to the rent of the land to be obtained by using the land until the land is transferred, and the judgment citing the whole or part of the claim becomes final and conclusive, in a case where the price of the land is remarkably high and the public burden, such as taxes, etc. is increased, and even if compared with the rent of the neighboring land, if special circumstances arise that seriously undermine the equity between the parties due to the change of economic circumstances, such as that the rent as cited in the judgment in the suit becomes unreasonable, even if compared with the rent of the neighboring land, it is reasonable to view that the land owner may file a new suit against the possessor, and claim the return of unjust enrichment equivalent to the difference between the rent as cited in the

[Separate Opinion]

In a case where a land owner claims a return of unjust enrichment equivalent to the rent, as a lawsuit for future performance against a person who possesses no legal cause, as a lawsuit for future performance, the parties concerned are practically unable to specifically assert and prove the amount of unjust enrichment equivalent to the rent to be incurred in the future. As such, the possibility of change is expected to some extent, and the amount of unjust enrichment equivalent to the rent to be incurred in the future would be different from that at the time of the time of the closing of argument. Under such premise, the court also determines the amount of the rent under such premise. Therefore, if the amount increases or decreases to the extent that the amount could not have been anticipated at the time of closing of argument, due to changes in economic conditions, etc., and the amount of the previous suit is considerably reasonable, such change shall be deemed to have newly occurred after the reason that the previous suit could not be asserted until the time of closing of argument. Accordingly, the owner may seek the increased portion as a return of unjust enrichment, while the possessor may assert the exclusion of enforcement force as to the reduced portion as a lawsuit for objection.

Articles 202 and 229 of the Civil Procedure Act

Supreme Court Decision 71Da430 decided Apr. 30, 1971 (No. 199 ② Ch.402) (def.)

[Defendant-Appellee] Plaintiff 1 et al.

[Defendant-Appellee] Defendant 1 and 3 others

Busan High Court Decision 92Na3182 delivered on September 24, 1992

The judgment of the court below is reversed.

The case is remanded to Busan High Court.

The plaintiff's attorney's second ground of appeal is examined.

1. Summary of the reasoning of the judgment below

The lower court determined that the Defendant, on the ground that the Plaintiff had no ownership transfer registration at 1984.1.25, 198 with respect to the land of 13 times or more than 13,000 won and that the Plaintiff had no ownership transfer registration at 13,000 won and 19,000 won for 19,000 won for 4,00 won and 9,000 won for 19,00 won and 9,00 won for 13,00 won and 9,00 won for 19,00 won and 9,00 won for 19,000 won and 9,00 won for 7,00 won and 9,000 won for 4,00 won and 9,00 won and 9,00 won for 7,00 won and 9,00 won and 9,00 won for 7,00 won and 9,00 won for 1,00 won and 9,00 won.

The previous lawsuit and the lawsuit of this case are identical to the basic facts, and the possession of the defendant's land of this case is established both unjust enrichment and tort in accordance with the legal official point. Also, when comparing the previous lawsuit and the lawsuit of this case as a whole, the purpose of the lawsuit is the same as the selective cause of claim. Furthermore, the legal relationship, which is the cause of the claim, is identical to the judgment of the previous lawsuit (in the case of the previous lawsuit, it is apparent that the legal relationship, which is the cause of the claim, is "before purchase of land", and the reasons for the judgment, are the same as the judgment of the previous lawsuit (in the case of the previous lawsuit, it is clear that the plaintiff accepted the claim of unjust enrichment among the selective claims of this case), and dismissed the remainder of the claim, which is cited in the plaintiff's selective claim of return of unjust enrichment among the damages claims of this case, and it is reasonable to view that the dismissal of the claim of this case from the above cited part of the damages claim of this case is also necessary to determine the whole damages claim of this case as to the plaintiff's claim of this case without any special reason.

2. Determination of party members

A claim for future performance is filed against a person who occupies land without any legal cause by an owner of the land, and in a case where the possessor claims the return of unjust enrichment equivalent to the rent of the land to be obtained by using or benefiting from the land until the land is transferred, and the judgment citing the whole or part of the claim becomes final and conclusive, when the price of the land is remarkably increased after the closing of pleadings at the fact-finding court of the lawsuit, and the public burden, such as taxes, is increased, and even when compared with the rent of the neighboring land, if special circumstances arise which seriously undermine the equity between the parties due to the change of economic circumstances, such as the amount of rent quoted in the judgment in the lawsuit becomes unreasonable, even if compared with the rent of the neighboring land, the owner of the land may file a new lawsuit against the possessor, and claim the return of unjust enrichment equivalent to the difference between the rent of the land quoted in the judgment in the previous lawsuit, and

In other words, if the possessor of a parcel of land claims return of future unjust enrichment at a certain rate which may arise continuously until the possessor delivers the parcel of land to the person who occupies the parcel of land without legal cause, understanding to the purport of claiming unjust enrichment calculated on the basis of the rent of the parcel of land as at the time of the closing of argument would be consistent with the party’s reasonable intent. As such, it is impossible for the owner to prove unjust enrichment equivalent to the difference in the previous suit to be asserted in the previous suit because special circumstances where it was difficult for the possessor to anticipate at the time of closing of argument after the closing of argument because he did not deliver the parcel of land for a long time after the lapse of time, and thus, it is unreasonable for the owner to claim unjust enrichment in comparison with the reasonable rent of the previous suit. In light of the legislative purport of Article 628 of the Civil Act, which provides that “If the rent of the previous suit is unreasonable due to the increase or decrease in the public charge on the leased object or any other change in the economic situation, the parties may claim an increase or decrease in the future, and thus, it cannot be seen as one of the previous suit.

The previous decisions made otherwise in the Supreme Court Decision 71Da430 delivered on April 30, 1971 are to be modified.

Therefore, as alleged by the plaintiff, the court below should have deliberated and judged whether the amount of rent cited in the judgment in the previous suit was unreasonable due to the change in the economic situation after the closing of argument in the previous suit, and then should have judged whether the res judicata effect of the judgment in the previous suit affects the claim in this case. However, the court below determined that the res judicata effect of the judgment in the previous suit extends to the claim in this case only for the reasons as stated in the decision. Thus, the court below erred by misapprehending the legal principles as to the partial claim, which led to the misapprehension of the legal principles as to the partial claim, or by misapprehending the legal principles as to the res judicata effect, and it is obvious that such illegality has affected the judgment. Thus

3. Conclusion

In a case where a plaintiff appealed against a judgment of the appellate court that has dismissed both selectively joined claims or dismissed a lawsuit, the court of final appeal should reverse the original judgment in its entirety, if the court of final appeal recognizes that an appeal concerning one of the selective claims is well-grounded. Therefore, the court of final appeal shall reverse the judgment below which dismissed all of the lawsuits concerning multiple claims selectively joined without determining the remaining grounds of final appeal No. 1 of the plaintiff's attorney, and the case is reversed in its entirety, and the case is remanded to the court below for further proceedings consistent with this Opinion, except for a separate opinion by Justice Park Jong-ho, Justice Park Jong-ho

The separate opinion of Justice Park Dong-ho and Justice Park Jong-dae is as follows.

Although the same view is that res judicata of a previous suit does not extend to this lawsuit, it is different in its reasoning.

Since res judicata takes place on the basis of the time of the closing of argument in a final and conclusive judgment, if a new cause occurs after the closing of argument, it shall be natural in light of the theoretical scope of res judicata.

However, in the case of claiming the return of unjust enrichment equivalent to the rent in the future against a person who possesses land without any legal cause as a lawsuit for future performance against the land owner, it is practically impossible for the land owner to specifically assert and prove the amount of unjust enrichment equivalent to the rent in the future. Therefore, the possibility of the change is expected to be certain extent, and the amount of unjust enrichment equivalent to the rent in the future which will occur in the future would be different from that at the time of the closing of argument, and the court will also determine the amount of the rent in the above premise.

Therefore, if the amount of money increases and decreases to the extent that it could not be expected at the time of closing argument due to changes in economic circumstances, etc., and the amount of money cited in the previous suit became considerably reasonable, such changes in circumstances shall be deemed to have newly occurred after the reason that could not be asserted until the closing of argument in the previous suit. Therefore, the owner may seek the increased portion of money as unjust enrichment return, whereas the possessor may claim the exclusion of executive force as to the reduced portion as a lawsuit of objection.

Since the standard market price of res judicata is the time of the closing of argument in a final and conclusive judgment that all owners or occupants may file a lawsuit for a new reason that occurred after the closing of argument in a final and conclusive judgment, the legal fiction of partial claims for which reservation has been reserved as stated in the Majority Opinion is unnecessary.

In the instant case, if the price of the instant land and its neighboring land was increased after the judgment of the previous suit became final and conclusive as the Plaintiff’s assertion, and the amount equivalent to the rent for the instant land was remarkably increased, and if the amount equivalent to nine times the amount cited in the judgment of the previous suit was close to nine times the amount cited in the judgment of the previous suit, this constitutes a new case where a cause that could not be asserted at the time of the closing of argument in the previous suit occurs. Therefore, regardless of whether a claim in the previous suit can be seen as a partial claim, the res judicata effect of the judgment of the previous suit shall not extend to the claim in this case seeking payment of the increased amount due to such change of circumstance

In conclusion, the judgment of the court below is erroneous in the misapprehension of legal principles as to the trial scope of res judicata or incomplete hearing, and in this respect, the judgment of the court below cannot avoid reversal.

Justices Park Jong-young (Presiding Justice) (Presiding Justice) Park Jong-young (Presiding Justice) Park Jong-ho, Kim Jong-ho, Kim Jong-ho, Kim Jong-ho, Kim Jong-ho, Kim Jong-ho, Kim Jong-ho, Kim Jong-ho, Park Jong-ho, Park Jong-