1. The part of the judgment of the court of first instance against the defendant shall be revoked.

2. The plaintiffs' claim corresponding to the above revocation part is filed.

1. The reasoning for this part of the lower court’s reasoning is as follows, except for correcting “the Plaintiff’s side” of the fourth five pages of the judgment of the first instance as “the Defendant’s side,” and therefore, the corresponding part of the reasoning of the judgment of the first instance is identical to the corresponding part of the judgment. As such, this part of the reasoning is

2. The parties' assertion

A. At the time of the purchase and sale contract of this case, D, the actual party of the defendant and the defendant, was aware that the retaining wall of this case was installed inside the boundary of the land of this case and the area that can be actually used as a site is less than 668m2, but was falsely explained to the plaintiffs as the area of 717m2.

The plaintiffs entered into the sales contract of this case by fraud or at least under mistake on the area of the land of this case. Accordingly, the above sales contract is cancelled by the delivery of a copy of the complaint of this case pursuant to Articles 109 and 110 of the Civil Act. The defendant shall pay to the plaintiffs the sum of the purchase price and construction expenses, additional payments for construction works, additional payments for seizure execution, interest payment for the unpaid balance, acquisition tax and property tax, and delay damages for such payment. The defendant shall be liable to perform the registration procedure for cancellation of the registration of the establishment of a new mortgage of this case.

[Plaintiffs, as the primary mistake, seek the return of unjust enrichment, such as the amount already paid, etc., as the effect of cancellation of a contract by fraud. However, the assertion of a cause without legal basis in a claim for restitution of unjust enrichment is merely an attack against a single subject matter of lawsuit (see Supreme Court Decision 2000Da5978, May 12, 2000). As such, the primary and conjunctive claims sought by the Plaintiffs in this case are merely a different attack against a single claim. Thus, this part of the Plaintiffs’ primary and primary claims are considered to have different ways of attack.