A. From May 2017 to June 2017, the Plaintiffs concluded a sales contract with the Defendant respectively with respect to one unit of N apartment O, respectively, as follows.

Each apartment unit that the plaintiffs purchased (hereinafter referred to as "each apartment unit of this case") was the sales price of KRW 234 million, exclusive area of KRW 84 square meters, and the designation period of occupancy was from January 25, 2019 to March 10, 2019.

The number of units of the Plaintiff’s contract date No. 1 A 1 B B B on June 2, 2017, May 18, 2017, Q C C C 3 C 4D on June 4, 2017, June 25, 2017: Uho 7 G G 7 G on May 16, 2017, May 16, 2017, h 8 H 9 I 8 H 88 H 5 G sale (each 1/2 shares) on May 18, 2017 on the joint sale (each 1/2 shares) on May 10, 201 G 11 K on June 20, 2017.

B. At the time of each of the above sales contracts, the Defendant prepared and issued to the Plaintiffs a certificate of premium security (hereinafter “instant certificate”) with the following contents as follows:

The amount of premium guarantee: 10,000,000 won guarantee method and the amount of premium guarantee by type where the premium is less than the amount of premium guarantee by type of insurance, if there is no premium payment or premium, the payment and payment date by type of insurance shall be within 60 days from the time of calculating the sale and purchase tax - the amount of premium calculation and sale - the sale price by floor - the method of calculating the market price at the end of six months from the month in which the date of calculating the market price at the time of sale and purchase of the Z bank's real estate and the date of sale on the basis of apartment at the time of sale and purchase = [the average price at the time of sale and purchase x 90%) [the average price at the time of purchase and sale x 10%) x 3, and 4 years old shall be the average price at the time of sale and purchase - the difference between the base amount at the time of sale and purchase - the amount at the time of sale and purchase - the amount at each floor shall be paid at the market price.

C. The sale price of each apartment of this case calculated according to the method of calculating the sale price under the confirmation document of this case is not only 230,2200,000 won, which is the base date, but also 230,000 won, which is lower than the sale price, to the present time.