1. Revocation of the first instance judgment.

2. The plaintiff's claim is dismissed.

3. All costs of the lawsuit shall be borne by the Plaintiff.

1. The defendant asserts that the judgment on the previous defense on the merits is not the defendant but D since it was not the defendant, the defendant is not eligible to be a party.

In a lawsuit for performance, the plaintiff's standing as a party itself is the plaintiff's own claim and the judgment is absorbed into the judgment of the propriety of the claim. Thus, the claimant of his claim for performance is a legitimate plaintiff and the person asserted as a person responsible for performance is the defendant.

(See Supreme Court Decision 88Meu26499 delivered on July 25, 1989. As to the instant case, since the health class and the instant case are lawsuits for performance, the Defendant asserted as the obligor has the standing to be a party.

Therefore, the defendant's defense prior to the merits is without merit.

2. Judgment on the merits

A. On November 2015, the Plaintiff asserted that, by being awarded a contract with the Defendant for the construction cost of 72,000,000 won of the 13-point multi-household housing on the ground of Samsung-si, the Plaintiff supplied the 13-point kiken and the stalth of the 13-point kids (combined board, tinboard, etc.).

Therefore, the Defendant is obliged to pay the Plaintiff the above additional construction cost of KRW 15.9 million (=Wnch 5.9 million Won) and damages for delay.

B. According to each of the evidence Nos. 2, 5, and 6, the fact that the Plaintiff received ownership No. 4 G of the F Building No. 4 of the land No. 2, E and 2, from the Defendant on Nov. 23, 2016, in lieu of the construction cost of the apartment house No. 3, the Defendant constructed in lieu of the construction cost of the apartment house No. 3, 196.

However, the following circumstances, which can be known through the overall purport of the statements and arguments in the evidence Nos. 1 through 4 and 6, ① The defendant and the defendant's representative director are separate business operators who have completed their respective business registrations, ② The construction contract document for the construction project is written by D, not the defendant, as the contractor, at the time when the plaintiff first concludes the construction contract for the multi-household C on the ground of the racing.