1. The plaintiff's claim is dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

1. Basic facts

A. On October 28, 2013, the Plaintiff entered into a sales contract with the Defendant to purchase “E kindergarten” (the founder of the instant kindergarten; hereinafter referred to as “the instant kindergarten”) that is a facility for the elderly on the third floor of reinforced concrete D’s lub roof, Busan, Daegu, Busan, to purchase from the Defendant (hereinafter referred to as “instant sales contract”) 2.24 billion won (the down payment of KRW 120 million per day, the intermediate payment of KRW 120 million, the first intermediate payment of KRW 30 million on November 28, 2013, the second intermediate payment of KRW 820 million on March 1, 2014, and the remainder of KRW 1 billion on March 1, 2017).

B. After that, on February 2, 2016, the Plaintiff entered into an agreement with the Defendant on the following terms and conditions (hereinafter “instant agreement”).

1) The Plaintiff recognized the compensation amount of KRW 240 million due to the rescission of a contract. 2) The Defendant shall return the remainder of KRW 1.3 billion, excluding the above amount, out of KRW 1.54 billion paid, to the Plaintiff. However, the Plaintiff shall return the remainder of KRW 50 million by the end of February 2016, and KRW 100 million by the end of March 2016, and the remainder of KRW 1.150 million shall be returned within at least four years, but the Plaintiff shall not demand a compulsory repayment to the Defendant in extenuating circumstances.

C. Under the instant agreement, the Plaintiff received a total of KRW 150 million from the Defendant from March 2016 until March 2016.

[Ground of recognition] Facts without dispute, Gap evidence Nos. 1, 2, 3, Eul evidence No. 1-1, 2, and 3, the purport of the whole pleadings

2. The Plaintiff’s assertion that the instant sales contract is a sales contract for “a teacher,” which is a property prohibited from buying and selling and offering collateral under the Private School Act, and null and void in violation of the mandatory law. As such, based on the instant sales contract, the Defendant’s purchase price of KRW 1.39 billion (i.e., KRW 1.., KRW 1.540 million - KRW 150 million), based on the instant sales contract, is money that the Defendant received from the Plaintiff without any legal ground, and the Defendant’s claim for return of unjust enrichment against the Defendant is part of the amount of KRW 20