1. The plaintiffs' primary claims and conjunctive claims are all dismissed.

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

(b)in the sale, the buyer will pay the purchase price as follows:

The contract amount of KRW 3,800,000,000 for the down payment of KRW 200,000 is paid and received at the time of the contract. The contract amount of KRW 3,600,000 for the remainder of the Defendant (Evidence A 3) was stated as of April 30, 2015 in the initial contract and sales contract (Evidence A 3) on May 30, 2015, but it appears that the payment date for the remainder was extended and revised by agreement between the Plaintiffs and the Defendant.

A seller of payment under Article 2 shall deliver all documents necessary for the registration of ownership transfer to a buyer simultaneously with the receipt of the balance, and the order of the object of sale shall be April 30, 2015.

Section 4. The seller shall compensate for the amount of the down payment at the time of the termination of the contract, and the buyer shall waive the contract and shall not demand the return thereof at the time of the termination, and shall terminate this contract.

Article 6. No objection shall be raised after the remainder of Article 7 attached to the special agreement exceeds the fixed date.

Article 7 was inserted into several instruments.

* Matters of special agreement

1. The above contract shall be transferred by assignment to the defendant corporation under the mutual agreement.

2. The intermediate payment and balance for the sale and purchase of the instant real estate shall be paid for loans from financial institutions within the balance date.

3. If the buyer requests the necessary documents related to the purchase of the instant real estate, the seller shall cooperate with him.

(4) The seller is not involved in the intermediate payment and the balance in the sale of the instant real estate and is responsible for all of the buyers.

C. On October 24, 2016, the Deceased who represented the Defendant in relation to the death of the Deceased and the conclusion of the first sale contract.

On February 26, 2017, the Plaintiffs and the Defendant created a private loan of KRW 4.5 billion in the name of the Defendant with the instant real estate as collateral. However, the Plaintiffs are liable for the said loan, and the Defendant is liable for the said loan, and the agreement to purchase the instant real estate by paying KRW 3.8 billion among them to the Defendant is below the agreement to purchase the instant real estate.