1. Revocation of the first instance judgment.

2. The plaintiffs' claims against the defendant are all dismissed.

3. The total cost of the lawsuit.

1. The reasoning for this part of the facts of recognition is the same as that of the judgment of the court of first instance, and thus, this part is cited in accordance with the main sentence of Article 420 of the Civil Procedure Act.

2. The parties' assertion

A. The Plaintiffs paid KRW 37 million to the Defendant on January 26, 2015 as the instant real estate sales brokerage commission, in addition to the amount of KRW 70 million paid to the Defendant on January 26, 2015. On April 1, 2015, the Plaintiffs paid KRW 37 million in total in the name of the price for which a false tax invoice was issued. The Defendant is obligated to return to the Plaintiffs the amount of KRW 30 million received in return for receiving the false tax invoice as above.

Since the defendant deceivings the plaintiffs and defrauds the above 30 million won, it is obligated to pay the plaintiffs 30 million won as compensation for damages caused by illegal acts.

B. On April 1, 2015, the Plaintiffs concluded a real estate consulting service contract with the Domin Global or Green Design Co., Ltd., and issued a tax invoice on the consulting service price from the Dominti Design, and paid KRW 30 million to Green City Design on April 1, 2015 as the expenses for the issuance thereof.

Since the defendant served as a delivery of the above 30 million won that the plaintiffs paid to Green City Design, the defendant's claim of this case against the defendant is improper.

3. Determination

A. The main text of Article 746 of the Civil Act provides that “If a property is provided or labor is provided for an illegal cause, the return of the benefit shall not be demanded.”

Therefore, if there is a benefit due to an illegal cause stipulated in Article 746 of the Civil Code, the person who provided the benefit, unless the illegal cause exists only for the beneficiary, or the illegality of the beneficiary is significantly greater than that of the provider, is allowed to claim the return of the provider.