2. All of the plaintiff's claims are dismissed.

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

A. The Defendants, who are married couple, had, through a licensed real estate agent, set up one apartment bond located in Sejong Special Self-Governing City (hereinafter “instant apartment bond”) in the form of KRW 590 million as a relic, and the Plaintiff expressed his intention to purchase the instant apartment bond to E through a licensed real estate agent D.

B. Since then, D and E took contact on October 9, 2018, setting the date of preparation of a sales contract as 4 p.m., and the Plaintiff remitted KRW 5 million to Defendant C’s account on October 5, 2018.

C. On October 8, 2018, the Defendants transferred the Plaintiff’s intent not to sell the instant apartment through E to the Plaintiff’s side, and transferred KRW 5 million received from the Plaintiff on October 9, 2018 to the Plaintiff’s account.

On October 17, 2018, the Plaintiff sent a content-certified mail demanding that the Defendants pay an additional penalty of KRW 5 million in addition to the amount of KRW 5 million returned due to unilateral destruction of the sales contract, and the said content-certified mail reached the following day.

[Ground of recognition] Facts without dispute, entry of Gap evidence 2 through 5 (including additional numbers), witness D's partial testimony, the purport of the whole pleadings

2. 원고의 주장 요지 원고와 피고들은 이 사건 아파� 5억 9,000만 원에 매매하기로 하는 계약을 체결하고 원고는 피고들 명의의 계좌로 계약금 500만 원을 송금하였음에도 피고들은 일방적으로 위 매매계약을 해제하였다.

Therefore, the Defendants are obligated to pay to the Plaintiff the remainder of five million won and damages for delay, excluding the remainder of five million won already paid, out of the total sum of the down payment of KRW 10 million as a penalty, to the Plaintiff.

3. In order to establish a judgment contract, it is required that there exists a mutual agreement between the parties, and such mutual agreement is not necessary with respect to any matter constituting the content of the contract in question, but is an essential matter or important matter.