A. The Korea National Housing Corporation (the Korea National Housing Corporation and the Korea Land Corporation are merged with the defendants on October 1, 2009; hereinafter collectively referred to as the "Defendant") obtained approval from the Gyeonggi-do Governor for a housing site development project implementation plan for the government housing site development project zone A (hereinafter referred to as the "instant zone") on November 13, 1995. On May 30, 1997, the approval was obtained for a housing site development project plan for the construction of public apartment units B in the instant zone. On April 11, 200, the approval for the alteration of the housing site development project plan was obtained in order to construct public rental apartment units on the B.

B. On October 1, 1998, the Defendant first announced the invitation of occupants on the C-ground D Apartment (hereinafter “the apartment of this case”) in order to rent the apartment of this case on April 18, 200. On October 16, 2000, the Defendant completed the construction of the apartment of this case and leased the apartment of this case to the Plaintiffs for five years as the publicly constructed rental house.

C. On December 2005, when the mandatory lease period of the apartment of this case has expired, the Defendant applied the standard construction cost to the construction cost of the apartment of this case, and the housing site cost was converted for sale at pre-sale price with 100% of the development cost.

Plaintiff

78. On December 2005, E, G, and H concluded each sales contract (G entered into each of the instant apartment units on No. 502, No. 404, and H entered each of the instant apartment units on No. 503, No. 704, respectively; hereinafter “each of the instant sales contracts”).

E. The Plaintiffs paid the purchase price to the Defendant on the basis of the housing price calculated based on the money stated in the “LH Construction Costs” column for the total amount of unjust enrichment by each Plaintiff, and then paid the price to the Defendant on the “registration date prior to the transfer date” under the same Table.