A. On September 18, 2002, the Defendant acquired the ownership of the Yangcheon-gu Seoul Metropolitan Government C Apartment No. 101, 1002 (hereinafter “instant apartment”). On August 9, 2016, the Defendant completed the registration of ownership transfer on September 30, 2016 to D and E, respectively.

B. On June 2016, the Defendant requested F, a licensed real estate agent, to sell the instant apartment.

C. On July 29, 2016, the Plaintiff found an apartment to be purchased for residential purposes at the time was introduced and examined the apartment of this case from F on July 29, 2016, and then transferred the aggregate amount of KRW 10 million in total and KRW 20 million in total to the Defendant on July 30, 2016 on the following day.

[Grounds for recognition] Gap evidence 2, 5, Eul evidence 1-1 to 5, and the purport of the whole pleadings.

2. The parties' assertion

A. (1) On July 29, 2016 between the Plaintiff and the Defendant, the sales contract was concluded on July 29, 2016, setting the down payment of KRW 95 million, KRW 950 million, KRW 9550 million, and the outstanding payment date on October 2016.

However, on September 30, 2016, the defendant sold the apartment of this case to a third party, and the defendant's obligation to transfer ownership to the plaintiff became impossible.

Therefore, the Defendant is liable to the Plaintiff for damages due to nonperformance.

(2) The amount of KRW 20 million that the Plaintiff remitted to the Defendant by the conjunctive claim is merely a provisional contract amount paid for the purpose of concluding a sales contract, and cannot be deemed as a cancellation amount.

As long as the conclusion of a sales contract between the plaintiff and the defendant has been displayed, the defendant must return the above KRW 20 million to the plaintiff as unjust enrichment.

B. On July 29, 2016, the Plaintiff and the Defendant concluded a sales contract with respect to the instant apartment as of the end of October 2016, setting the sales contract amount of KRW 20 million, KRW 955 million, and the remainder payment date.

In addition, the Plaintiff paid the Defendant the sum of KRW 20 million to the down payment on July 29, 2016 and July 30, 2016.