1. The plaintiffs' claims against the defendants are all dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Basic facts

A. On December 1, 2015, the Plaintiffs entered into a sales contract with Defendant C, and the Gangseo-gu Seoul Metropolitan Government E large 179 square meters and multi-family houses on its ground (hereinafter “instant building”) owned by the said Defendant.

2) As to the sales amount, the sales contract is set at KRW 864,00,000 (hereinafter “instant sales contract”).

(2) The Plaintiffs paid KRW 200,000,000 out of the above sales price to Defendant C, as a licensed real estate agent.

B. On March 10, 2016, the Plaintiffs notified the Defendants that the instant sales contract was revoked due to fraud or mistake. At that time, the said notification reached the Defendants.

[Reasons for Recognition] Facts without dispute, entry of Gap evidence 1 through 4 (if there are provisional numbers, including each number; hereinafter the same shall apply) and the purport of the whole pleadings

2. The plaintiffs' assertion

A. 1) Claim against Defendant C 1) The sales price of the instant sales contract for the primary claim in comparison with the market price in the vicinity of the instant building, which is a monthly fashion (this fact is referred to as “first fact”).

A) The walls of the third floor and the rooftop floor of the instant building consisting of brick walls different from those entered in the public account book (refinite concrete) (this fact is referred to as “second fact”).

) There are illegal expansions on the rooftop floor of the above building (this fact is referred to as "third fact").

(2) Since Defendant C entered into the instant sales contract by concealing the above facts and causing fraud or mistake, the above sales contract was revoked and the return of unjust enrichment was claimed for the payment of KRW 200,000,000,000, including the construction cost of KRW 7,000,000 and the construction cost of KRW 207,00,000 paid by the Plaintiffs on behalf of the said Defendant, and damages for delay thereof. (2) As above, the instant building for preliminary claim is subject to Article 580 of the Civil Act.