A. On April 6, 2015, the Plaintiff entered into a sales contract with the Defendant to purchase KRW 252,640,000 (hereinafter “instant sales contract”) the sales right (hereinafter “instant apartment”) of the Gangnam-gu Seoul Metropolitan Government C Apartment 605,604 (hereinafter “instant apartment”) from the Defendant, and paid KRW 22,640,000 to the Defendant’s bank account under the name of the Defendant’s order on the date of the contract. On May 7, 2015, the Plaintiff paid KRW 20,640,000 to the Defendant’s account under the name of the Defendant, and on the same day, issued a check of KRW 21,000,000 to the Defendant.

B. On September 9, 2015, the Defendant presented to the Plaintiff the official text of the Seoul Special Metropolitan City SH Corporation (hereinafter “SH Corporation”)’s “Guidance on Claim for Settlement and Settlement of Accounts Following the cancellation of a housing contract for sale in lots” (hereinafter “instant official text”). The instant official text contains the content that “The sales contract for the instant apartment that was concluded on December 23, 2014 by E was revoked as of September 9, 2015.” As such, the sales contract for the instant apartment that was concluded on September 23, 2015 after deducting penalty from the amount to be paid for sale in lots was revoked, the Defendant filed an application for the remaining settlement amount after deducting penalty from the amount to be paid for sale in lots.”

C. Meanwhile, the case where illegal transactions in the subscription passbook in the name of a third party and resells the right to sell apartment units secured by the above subscription passbook was discovered through the intelligence criminal investigation team of the Seoul Special Metropolitan City Police Agency. The so-called subscription passbook business operator and real estate broker divide the proceeds from resale, secure the subscription passbook in the name of a third party and the right to sell apartment units, and sell it as if it were the normal right to sell apartment units.

As it was discovered that the sales right of this case was also exposed to the above circumstances, the initial sales contract was revoked, and the plaintiff was refunded KRW 135.6 million from the defendant.

[Ground of recognition] Facts without dispute, entry of Gap evidence 1 to 4, purport of the whole pleadings

2. Summary of the parties' arguments

A. Plaintiff 1.