1. All of the plaintiffs' claims are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Basic facts

A. On September 5, 2005, Defendant C entered into a sales contract with Nonparty F to sell 3/13 shares, one-third of which is one’s own shares (hereinafter “instant real estate”) out of 18,589 square meters of land in Gangnam-gu Seoul Special Metropolitan E Forest and E Forest, located within the land transaction permission zone, as KRW 390,000,000 for the buyer’s “non-party 1” and the purchase price.

The special terms and conditions of the above sales contract include the following: “The seller cooperates with the buyer at the time of change of the buyer’s name at the time of payment of the balance.”

According to the above sales contract, F paid to Defendant C the down payment of KRW 80 million on the date of conclusion of the above contract, and the intermediate payment of KRW 50 million on September 22, 2005.

B. When it was difficult for F to pay the balance of the instant real estate, upon request from G, etc. who is the branch, the debtor on March 28, 2006, determined the maximum debt amount as KRW 465 million with respect to the instant real estate as the Plaintiff B and the debtor on the ground of the mortgage contract on the same date, and the registration of the establishment of a neighboring mortgage and the debtor on the ground of the mortgage contract with Nonparty H as the guarantor, respectively, and the loan was received from Nonparty G as the guarantor, and on the same day, the amount of KRW 260 million out of the loan was paid to Defendant C as the remainder under the said contract.

Around that time, the sales contract with regard to the instant real estate was re-established by the seller, Defendant C, the buyer “Plaintiff B and one other,” the joint buyer H, and the purchase price of KRW 390 million.

(c) F. F. H.D.

When it was impossible to repay the I loan to the plaintiffs as of January 16, 2009, the sales contract was issued, which was prepared as of January 16, 2009, with regard to the above real estate by the seller, the defendant C, the purchaser, the purchaser, the plaintiff B, the purchaser, and the purchase price of the plaintiff B, the 390 million won.

Defendant D, regarding the instant real estate on February 4, 2009, set forth the obligor C, the maximum debt amount of KRW 40 million, and based on the mortgage contract on the same date.