A. F, on April 26, 2013, when G stock companies obtain a loan of KRW 375 million from the H bank, F guaranteed that the company’s loans to the said bank to the extent of KRW 90 million.

The plaintiff acquired the above claim against the above company and F by transfer of the above claim against the above company and F, and the amount of the claim against the plaintiff F is KRW 90 million at present.

B. On October 23, 2013, F entered into a mortgage agreement with the Defendants regarding the real estate listed in the separate sheet (hereinafter “instant apartment”) with the Defendants, setting the maximum debt amount as KRW 300 million, and completed the registration of the establishment of a neighboring mortgage as Seoul Northern District Court’s receipt of the Seoul Northern District Court No. 97316 on October 24 of the same year.

C. At the time when F entered into a contract to establish the said mortgage with the Defendants, the instant apartment was set up by F as a collateral of I Co., Ltd., setting the maximum debt amount at KRW 264 million, and F did not have any specific property other than the apartment of this case at the market price of KRW 370 million.

The F, in addition to the above guaranteed obligation at the time, has been in excess of the obligation due to the K Bank, K, etc.

On April 10, 2017, the apartment house of this case was sold in the auction case of the Seoul Northern District Court, and the Defendants received dividends of KRW 180 million in the second priority as a mortgagee in the above procedure.

2. Determination on this safety defense

A. The gist of the defense is that F entered into a mortgage contract with the Defendants on the apartment of this case and completed the registration of the establishment thereof on the ground that it was fraudulent act, and the cancellation of the contract and its restoration to its original state against the Defendants, and the Defendants sought payment of the amount equivalent to the Plaintiff’s claim out of the amount distributed as a collateral in the auction procedure. However, since the registration of establishment of a mortgage established pursuant to the above mortgage contract was cancelled due to a compulsory auction of real estate, the Plaintiff did not have a benefit to seek cancellation of