All appeals concerning the plaintiff's primary claim and the first preliminary claim are dismissed.

1. As to the appeal as to the primary claim

The plaintiff filed an appeal against the main claim of the judgment below. However, there is no indication of the grounds for appeal in the petition of appeal and no statement of the grounds for appeal is found in the appellate brief.

2. As to the grounds of appeal on the first preliminary claim, the lower court rejected the Plaintiff’s claim for return of unjust enrichment on the ground that, on the grounds as indicated in its reasoning, it is insufficient to readily conclude that the instant sales contract falls under the invalidity as a matter of course, and even if the obligee of the construction cost to be paid by the Plaintiff is the Defendant or D Co., Ltd. (hereinafter “D”), the registration of ownership transfer cannot be deemed as unjust enrichment.

Examining the reasoning of the lower judgment in light of the records, the said determination by the lower court is justifiable, and contrary to what is alleged in the grounds of appeal, the lower court did not err by failing to exhaust all necessary deliberations or by misapprehending relevant legal principles

3. As to the ground of appeal on the second preliminary claim

A. According to the reasoning of the lower judgment, the Plaintiff concluded a construction contract with D on September 23, 2009 for the construction of a new automobile maintenance plant and a gas station on the instant land owned by the Plaintiff (hereinafter “instant construction”). On the same day, the Plaintiff concluded an international trust agreement with the International Trust Co., Ltd. (hereinafter “International Trust”) for the purpose of securing the obligation for the construction cost, and completed the trust registration on September 24, 2009. ② The Plaintiff did not enter the construction cost of the instant land into an additional construction contract for the increase of KRW 1,372,250,000 for KRW 20,000 for each of the instant real estate purchased with D on October 15, 201. ③ The Plaintiff did not request the Defendant to transfer the ownership of each of the instant real estate to the trust property owned by 10,000, 200, 300,0000, 10,0000,000 won for each of the instant real estate to the Defendant.

B. Based on the above facts, the court below rejected the Plaintiff’s revocation of the Plaintiff’s sales contract, on the ground that: (a) the Plaintiff and C and the Defendant did not intend to actually exchange KRW 1,372,250,000 of the purchase price on the part of the building including the instant building at the time of concluding the sales contract; (b) the Plaintiff concluded the instant sales contract at the time of transfer of each of the instant real estate including the instant land; (c) the Plaintiff’s assertion on the rescission of the instant sales contract cannot be accepted as erroneous; or (d) the registration of each transfer of ownership was of a nature to secure the Plaintiff’s performance of the Plaintiff’s obligation for the payment of the construction price; (b) the Plaintiff did not immediately transfer the ownership of the instant real estate to the Plaintiff and the Defendant, a truster, at the time of signing the instant sales contract; and (c) determined that Article 2 of the Special Clause of the Real Estate Security Trust Act, which was the first beneficiary of the instant trust agreement and the Defendant, the first beneficiary of the instant trust agreement, to transfer the ownership of the instant trust agreement to the Plaintiff.

In addition to these facts, the Plaintiff, C, and the Defendant agreed to treat the Plaintiff’s agreement to transfer the Plaintiff’s ownership of the instant building to C and the Defendant in lieu of the Plaintiff’s performance of the obligation for the payment of the construction price as of October 21, 2010, as the Plaintiff transferred the ownership of the instant building to C and the Defendant, namely, the Plaintiff’s transfer of ownership of the instant building to C and the Defendant, and the said obligation for the payment of the construction price is extinguished, and as a result, C and the Defendant also paid KRW 1,372,250,000 to the Plaintiff, regardless of the agreement stipulated in the real estate security trust agreement as of October 21, 2010, it is reasonable to deem that the instant sales

However, there is no reason to deem that C and the Defendant had the right to transfer the ownership of the instant building in lieu of performing the Plaintiff’s obligation to pay the construction price at the time of the conclusion of the instant sales contract, so even if the Plaintiff transferred the ownership of the instant building to C and the Defendant pursuant to the instant sales contract, the Plaintiff’s obligation to pay the construction

As long as the obligation of the Plaintiff is not extinguished, it cannot be deemed that C and the Defendant paid the Plaintiff the purchase price of KRW 1,372,250,000 for the portion of the building including the instant building, so it is reasonable to view that C and the Defendant still bear the obligation to pay the said purchase price to the Plaintiff in reality.

However, according to the records, the defendant did not pay the above purchase price of KRW 1,372,250,000 to the plaintiff. The plaintiff's written brief dated September 17, 2013 containing the plaintiff's notified payment of the above purchase price was served to the defendant around that time. Nevertheless, since the defendant did not pay the above purchase price, the plaintiff's written brief dated September 24, 2013 containing the plaintiff's declaration of intent to cancel the sales contract of this case was served to the defendant around that time. As seen earlier, since the plaintiff fully performed his/her obligation under the sales contract of this case, the above sales contract of this case should be deemed to have been lawfully rescinded by delivery of the written brief dated September 24, 2013.

D. Nevertheless, the lower court rejected the Plaintiff’s rescission order. In so doing, the lower court erred by exceeding the bounds of the principle of free evaluation of evidence against logical and empirical rules, and by misapprehending the legal doctrine on interpretation of legal acts and requirements for the occurrence of obligation to pay the purchase price, thereby adversely affecting the conclusion of the judgment. The allegation contained in the grounds of appeal

4. Conclusion

Therefore, the part of the judgment below regarding the second preliminary claim is reversed, and that part of the case is remanded to the court below for further proceedings consistent with this Opinion. The plaintiff's primary claim and the first preliminary claim are all dismissed. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Kim Yong-deok

Justices Kim Jae-han

Chief Justice Kim Jong-il