The judgment below is reversed and the case is remanded to Seoul High Court.

We examine the grounds of appeal.

1. According to the reasoning of the judgment below, the court below accepted the judgment of the court of first instance and acknowledged that the non-party D, who was the defendant's purchasing officer, temporarily transferred the debt to the defendant's account from the defendant's account in the name of E to the defendant's account on September 2003, it is difficult for the defendant to recover the claim in fact due to E. It is expected that the claim was returned to the defendant. There may be a problem if the claim is not recovered up to that time. The defendant's executive officer of the defendant's F would return the claim. The plaintiff sent the sum of KRW 126,190,880 to the defendant's account in the name of E five times. The court below determined that the plaintiff paid it to the defendant temporarily according to the end of the defendant's person in charge of the defendant, such as D, and received the amount of this case from the defendant's subrogation. Thus, the plaintiff's payment at the time of transfer was made by the plaintiff's subrogation to the defendant, without any legal ground.

2. However, it is difficult to accept the above determination by the court below for the following reasons.

Even according to the above facts acknowledged by the court below, the plaintiff accepted the request for subrogation because D would return the subrogated amount again. Accordingly, the plaintiff would be deemed to have made a temporary payment by subrogation and return the amount of subrogated amount from the defendant in the future. According to this, it is reasonable to view that the contract and return agreement between the plaintiff and D constitute a single contract as a corresponding relationship or a consideration relationship.

Therefore, the validity of the agreement shall be determined as a whole.