1. The plaintiff's claim that is changed in exchange in the trial is dismissed.

2. All costs of the lawsuit shall be borne by the Plaintiff.

1. The court's explanation on this part of the basic facts is identical to the corresponding part of the judgment of the court of first instance, and thus cite it as it is by the main text of Article 420 of the Civil Procedure Act.

2. The assertion and judgment

A. The Plaintiff’s assertion was transferred from D the status of the co-owner of the instant commercial building, but the Defendant’s co-defendant C (hereinafter “C”) at the first instance trial, unlike the content of the instant agreement, stated the sale price in the sales contract as at KRW 260 million lower than the actual transaction amount, and thus, the Plaintiff could not follow it.

Accordingly, the Plaintiff notified the Defendant of the purport that the instant down payment should be returned to the Defendant on or around December 8, 2014, and the Defendant is obligated to return the down payment already paid to the Plaintiff as unjust enrichment.

B. (1) First, we examine whether the Defendant is a party to the instant agreement.

who is the party to the contract is a matter of interpretation of the party involved.

(see Supreme Court Decision 2012Da4471, Nov. 29, 2012). In relation to the determination of contractual parties, if both parties agree with one another, the contractual parties should be determined according to their agreed intent. If both parties fail to agree, a reasonable person should be determined based on the specific circumstances before and after the conclusion of the contract, such as the nature, content, purpose, and circumstance of the contract.

(2) In light of the overall purport of the evidence duly admitted as above, the court below erred by misapprehending the legal principles as to the conclusion of the instant agreement with C, and exceeding the bounds of the legal principles as to the conclusion of the instant agreement, and exceeding the bounds of the legal principles as to the conclusion of the instant agreement, the court below did not err by misapprehending the legal principles as to the conclusion of the instant agreement with C, as otherwise alleged in the ground of appeal.