1. The plaintiff's appeal and the defendant's incidental appeal are all dismissed.

2. Costs arising from an appeal and an incidental appeal shall be respectively.

1. The grounds for the quoted decision of the court of first instance are the same as the grounds for the decision of the court of first instance, except for adding the same judgment as those as those as those as the stated in paragraph (2).

2. The Defendant asserts that the lawsuit of this case filed by the Plaintiff is unlawful or that the Plaintiff’s assertion is groundless, since the Plaintiff did not hold the claim for construction price against the Defendant as it transferred the claim for construction price against the Defendant to K Co., Ltd. and L Co., Ltd.

(1) As to the assertion, in a lawsuit for performance, the person alleged by the plaintiff as the person responsible for performance has the standing to be the defendant (see, e.g., Supreme Court Decision 94Da14797, Jun. 14, 1994). The defendant's argument ① is without merit.

Then, according to the reasoning of the argument, the Plaintiff sent a mail to the Defendant on June 14, 2017, stating that “The amount equivalent to KRW 64,00,000,000 from K Co., Ltd. was directly paid to L Co., Ltd., and the amount of each material was directly paid to L Co., Ltd.” and the fact that the Plaintiff, on June 14, 2017, stated the phrase “the transfer of the claim and the transfer of the claim, thereby giving consent to the direct payment.”

However, a thorough examination of the contents of the above postal service reveals that it is not a notification of the transfer of claims because it calls the Defendant to pay progress payment and requests the Defendant to pay the material price as part of the method of paying the progress payment. Such determination is not a notification of the transfer of claims. ① The above postal service does not have any relevant documents, such as the notice of the transfer of claims or the contract of the transfer of claims, ② the Defendant recommended the Plaintiff to receive KRW 97,458,662, which is calculated by the settlement amount of other accounts concerning the instant construction, as stated in the first instance court’s instructions, and ③ in fact K.