1. The plaintiff's appeal is dismissed.

2. The costs of appeal shall be borne by the Plaintiff.

Purport of claim and appeal

The first instance court.

1. The plaintiff's assertion

A. C did not receive KRW 5,188,948 for the amount of the goods, even if the goods were supplied to D Co., Ltd.

However, D Co., Ltd has the external form of a juristic person, but it merely takes the form of a juristic person. The substance of D Co., Ltd. is the defendant's personal company and its legal effect should belong to the defendant, so the above goods-price obligation is the defendant's obligation.

On the other hand, since the plaintiff acquired the claim for the price of goods from C to the defendant, the defendant is obligated to pay the price of the goods and the damages for delay to the plaintiff.

B. Pursuant to Article 401 of the Commercial Act, the defendant is jointly and severally liable with D Co., Ltd. to pay the above 5,188,948 won and damages for delay to the plaintiff.

2. Determination

A. In a case where one company is in the external form of a juristic person but merely takes the form of a juristic person, and in substance, it is merely an individual enterprise of another person behind the juristic person or it is used without permission for the purpose of avoiding the application of the laws against the person behind the juristic person, the denial of the responsibility of the person behind the juristic person by asserting that even if the act of the juristic person is an act of the juristic person, it is a separate personality between the company and the person behind the juristic person, and the legal effect of it is attributed only to the company, on the ground that the person behind the juristic person is a separate personality, shall not be permitted in violation of the principle of trust and good faith, and it shall be deemed that the person behind the juristic person as well as the person behind the juristic person

If the company seems to be only a private enterprise of another person behind the corporate personality, in principle, it is difficult to distinguish between the company and its hinterland from the property.