1. The part against Defendant C in the judgment of the first instance is revoked, and the Plaintiff (Counterclaim Defendant) corresponding to the revoked part is revoked.

1. The reasoning for the court’s explanation of this case is as stated in the reasoning of the judgment of the court of first instance, except for the following modifications or additions. Thus, it is citing this as it is in accordance with the main sentence of Article 420 of the Civil Procedure Act.

At the fourth bottom of the judgment of the first instance, the following shall be added:

“I notified the insurance money to be paid in advance in currency with Defendant B; Defendant B visited Defendant C’s maintenance business establishment 2-3 and appears to have confirmed the condition and progress of repair of Defendant C’s vehicle; Defendant C demanded the Plaintiff to pay parts in advance, and even if the repair was not commenced until 20 days after the date of the instant accident, Defendant C continued to leave the repair to Defendant C without replacing the maintenance business establishment, and even if the repair was not commenced until 20 days after the date of the instant accident, Defendant C continued to leave the repair to Defendant C, as follows.

Where a party to a contract directly provides a third party who has a different contractual relationship with the other party by shortening the performance process through the instruction of the other party to the contract (if the payment has been made under the so-called trimulse relationship, not only the payment has been made to the other party to the contract but also the payment has been made to the third party, so a party to the contract may not file a claim for return of unjust enrichment on the ground that he received the payment against the third party without legal grounds.

In such a case, if one of the parties can make a claim for return of unjust enrichment against a third party on the ground that there is a defect such as invalidity of legal relations of the party causing the performance against the contracting party, it is the transfer of risk burden under a contract concluded under his own responsibility to the third party, which is contrary to the principle of contract law.