The judgment of the court below is reversed.

The judgment of the first instance is revoked, and the lawsuit of this case is dismissed.

The plaintiff's total costs of litigation.

The grounds of appeal are examined.

1. Regarding ground of appeal No. 1

A. As a matter of principle, delivery by delivery to the person to be served at his domicile, residence, business place, or office of the person to be served (Articles 178(1) and 183(1) of the Civil Procedure Act), or by a service agency, if the person to be served was not present at the aforementioned place, such service may be made by supplementary service to his/her clerk, employee, or cohabitant, who is man of sense of judgment, as his/her employee, or cohabitant;

(Article 186(1) of the same Act. The supplementary service system is premised on a reasonable expectation that the document will be delivered to the principal by social norms in light of his/her intelligence and objective status, relationship with the principal even if the recipient receives the document.

However, in a case where there is a conflict of interests or conflict of interests between the principal and the receiving agent, it is difficult to reasonably expect that the receiving agent deliver the documents of lawsuit to the principal, and where the receiving agent who conflicts of interests is served the documents of lawsuit on behalf of the principal violates the principle of prohibition of bilateral representation. Thus, it shall not be deemed that the supplementary service may not be made to the receiving agent who has conflicting interests between the principal and the receiving agent who has conflicting interests in the lawsuit

B. According to the reasoning of the judgment below, the plaintiff received a seizure and collection order (hereinafter "the seizure and collection order of this case") as to the wage and retirement allowance claim against the defendant in B as the Incheon District Court Decision 2008TTT 208T 11989 on September 10, 2008 by using the debtor as the defendant, the third debtor as the defendant, the claim amount of KRW 60 million. The above court served the original copy of the decision of the seizure and collection order of this case as the defendant's principal office. The debtor of the seizure and collection order of this case and B is the defendant's office.