[2] The case holding that the res judicata effect of a protocol of recognition and recognition of a claim for the return of purchase price caused by the invalidation or cancellation of a sales contract cannot be said to affect a claim for ownership transfer registration under the sales contract

[2] The case holding that the res judicata effect of a protocol of recognition and recognition on a claim for the return of purchase price, which was made for the invalidation or cancellation of a sale contract, only arises with respect to the existence of a right to claim the return of purchase price, and it does not arise with respect to the invalidation or cancellation of a sale contract which is a prior legal relationship, which is a premise, and thus, the existence of a right to claim the registration of ownership transfer cannot be viewed as a subject-matter of a lawsuit which is inconsistent with the legal relations established in a prior suit, and that the legal relations which are the respective premises of a prior suit and a subsequent suit, which do not have res judicata effect, cannot be said to affect the subsequent suit on the ground that the validity or invalidity of

Even if the subject matter of a lawsuit brought after the previous suit is not identical, if the subject matter of a lawsuit brought after the previous suit is the subject matter of a lawsuit inconsistent with the established legal relationship in the previous suit, the effect of res judicata of the previous suit on the lawsuit brought after the res judicata of the previous suit (see Supreme Court Decision 2002Da44014, Dec. 6, 2002). However, res judicata of a final and conclusive judgment does not affect the conclusion of the judgment on the existence of a legal relationship brought after the previous suit and does not affect the existence of a legal relationship which is the premise thereof (see Supreme Court Decision 2002Da11847, Sept. 24, 2002). The legal relationship established in the previous suit refers to a legal relationship which has res judicata of the final and conclusive judgment, and it does not mean a legal relationship which is the premise thereof.

The court below determined that the Plaintiff’s claim for ownership transfer registration based on the premise that the sales contract of this case was null and void in a previous suit was final and conclusive inasmuch as the Plaintiff’s claim for ownership transfer registration based on the premise that the sales contract of this case was null and void in a previous suit, and the Plaintiff’s claim for ownership transfer registration based on the premise that the contract of this case was null and void or cancelled, was a final and conclusive legal relationship inconsistent with the legal relationship established in the previous suit, and thus, it contradicts the res judicata effect of the above recognition and recognition protocol.

However, res judicata of a protocol of recognition and recognition of a sales contract as to a claim for the refund of the purchase price, which has been caused by the invalidation or cancellation of a sales contract, only arises with respect to the existence of a claim for the refund of the purchase price, and does not arise with respect to the invalidation or cancellation of a sales contract which is a prior legal relationship, which serves as the premise thereof. The legal relationship in which res judicata effect of a protocol of recognition and recognition of a sales contract, which is a prior legal relationship, exists, is limited to the plaintiff's right to claim for the refund of the purchase price against the defendant. On the other hand, the subject matter of a lawsuit in this case is the existence of a claim for the transfer of ownership, and therefore the subject matter of a lawsuit in this case cannot be said to be the subject matter of a lawsuit in this case, and the legal relationship, which is a premise of each subject matter

Therefore, the lower court determined that res judicata effect of a protocol of recognition and recognition in a prior suit extends to the instant lawsuit, which erred by misapprehending the legal doctrine of res judicata, thereby adversely affecting the conclusion of the judgment.

2. Whether the instant claim violates the good faith principle

The Plaintiff filed a lawsuit claiming the invalidation or cancellation of a sales contract and seeking the refund of the purchase price, and filed a separate lawsuit claiming that the sales contract is valid for the purpose of gaining double benefit during the lawsuit, or agreed between the Plaintiff and the Defendant to have the sales contract invalidated or cancelled, or agreed to have the Plaintiff make an agreement between the Plaintiff and the Defendant null and void or rescind the sales contract, or sought the performance of the sales contract in violation of the principle of good faith in the absence of justifiable grounds to believe that the Plaintiff did not make a claim for the registration of transfer of ownership based on the sales contract, and in special circumstances, the Plaintiff’s filing of a lawsuit cannot be deemed to have violated the principle of good faith. However, as in the instant case, it cannot be deemed that the Plaintiff filed a lawsuit seeking the performance of the registration of transfer of ownership based on the sales contract in accordance with the sales contract while the Plaintiff filed a previous lawsuit on the grounds of invalidity or cancellation of the sales contract, and it is difficult to deem that the Plaintiff granted the Defendant

Even according to the fact-finding of the court below, the plaintiff's act of maintaining the previous suit and the previous suit in this case was due to the plaintiff's withdrawal of the previous suit, but the defendant's rejection of the previous suit was not effective due to the defendant's rejection of the previous suit, and the defendant's alteration of the previous suit in this case's attitude after the plaintiff lost at the court of first instance, and the previous suit was concluded by recognizing the plaintiff's claim for the previous suit. Ultimately, the circumstance that the plaintiff can be seen as a double benefit by winning both the previous suit and the previous suit in this case's winning of the previous suit and the previous suit in this case's acceptance of the previous suit's withdrawal of the previous suit's claim, and the defendant's act cannot be seen as a cause of the plaintiff's act. Thus, the plaintiff's maintenance of the previous suit in this case's previous suit after the plaintiff's refusal of the previous suit cannot be viewed as a violation of the good faith principle, and any unreasonable reason that the plaintiff's double benefit in this case's previous suit and the previous suit cannot be rejected.

Therefore, the lower court’s rejection of the Plaintiff’s claim on the ground that the Plaintiff’s lawsuit in this case was in violation of the good faith principle, and thus cannot be permitted, constitutes an unlawful determination that adversely affected the conclusion of the judgment.

3. Conclusion

Therefore, without further proceeding to decide on the remaining grounds of appeal, the judgment of the court below is reversed, and the case is remanded to the court below. It is so decided as per Disposition.

Justices Kim Hwang-sik (Presiding Justice)