A. On May 12, 201, the Defendants concluded a contract with the Plaintiff for the supply of KRW 52,490,000 (including value-added tax) (hereinafter “instant contract”) to purchase the instant apartment C, 307, and 1102 (hereinafter “instant real estate”), and on the same day, concluded a contract for the supply of the instant real estate to the Plaintiff at KRW 59,220,00 (including value-added tax). According to the instant contract and the instant supply contract, the Defendants paid the remainder of the sales contract to the Plaintiff for the down payment of KRW 73,00,000 on the date of the contract, the sales contract and the remainder of the contract for the supply of the instant real estate at KRW 730,000 (including the instant contract for the supply of the instant real estate at KRW 700,000,000,000 (the remainder of the contract for the purchase of the instant real estate at KRW 300,000).

B. At the time of the conclusion of the instant sales contract, the Defendants entered into a special agreement on the guarantee of premium guarantee (hereinafter “the instant special agreement on guarantee of premium”) with the Plaintiff and the Plaintiff to return the difference within the limit of KRW 50,000,000 in the event that the increased amount of the instant real estate price does not exceed KRW 50,000 after 2 years after the date of the instant sales contract (hereinafter “the instant special agreement on the guarantee of premium”). (ii) In the event the Plaintiff entered into a sales contract on more favorable terms than the terms of the instant sales contract on the same real estate as the instant real estate (excluding the instant real estate, the fourth floor, and the fourth floor) within 2 years from the date of the instant sales contract, the special agreement on the guarantee of the contract terms that the said conditions should be retroactively applied to the instant sales contract (hereinafter

C. At the time of the conclusion of the instant sales contract, the Plaintiff shall pay the Defendants interest calculated at a rate of 4.3% per annum on the money equivalent to 60% of the sales price of the instant real estate for 2 years. 49,148,480 won out of the sales price of the instant real estate under the pretext of supporting the Defendants for 2 years.