1. All appeals filed by the plaintiffs are dismissed.

2. At the preliminary claim of the plaintiffs added in the appellate court:

The reasons for this judgment of this court shall be the same as the judgment of the first instance.

(main sentence of Article 420 of the Civil Procedure Act): Provided, That any addition shall be made as follows:

1.At the fifth below the judgment of the first instance, the following shall be added:

The right to collateral security of this case is also the secured obligation to return the plaintiffs' obligation arising from the rescission of the contract of this case.

Even in the case of this case, the contract was rescinded upon the defendant's request for auction.

Therefore, if the defendant settles the penalty and the plaintiffs' damages (amount of late payment and late payment damages, brokerage commission) to be paid by the defendant pursuant to Article 12 (2) of the contract of this case, there is no money to be refunded by the plaintiffs.

Therefore, the right to collateral security of this case should be cancelled because there is no secured obligation.

Preliminaryly, the right to collateral security in the instant case is the secured obligation for the Plaintiffs’ repayment obligation arising from the rescission of the instant contract. If the Defendant calculated the penalty for breach of contract pursuant to Article 12(1) of the instant contract, the amount to be refunded to the Plaintiffs is KRW 365,106,539.

Therefore, the Defendant should cancel the instant right to collateral security after receiving KRW 365,106,539 from the Plaintiffs.

2.On the seventh day of the first instance judgment, the following shall be added:

Although the plaintiffs asserted that the damages for delay against the intermediate payment and the balance should be included in the plaintiffs' damages, there is a penalty provision under Article 12 (1) of the contract of this case, and the penalty for breach of contract is deemed as liquidated damages, so it is not possible to seek damages in excess of this.

Therefore, the plaintiffs' assertion is not accepted.

In addition, the plaintiffs claim that they pay only their brokerage fees of the contract of this case, and that if the defendant asserts the termination of the contract, the defendant bears half of them in accordance with the concept of fairness.