1. The judgment of the first instance, including the successor participation by the plaintiff succeeding intervenor, is modified as follows.

Basic Facts

The relevant plaintiff of the parties is a representative director of B Co., Ltd. (hereinafter referred to as “B”), C is a kind of the plaintiff, and the defendant is a corporation established for the purpose of soil construction business, etc.

In around 2004, Sung-gun, including the establishment of a pledge on the Seoul Guarantee Insurance, demanded the Plaintiff to guarantee the deposit for recovery expenses when it permitted the gathering of earth and rocks on D land, etc. (hereinafter “the gathering of earth and rocks”). On March 10, 2004, the Plaintiff entered into a guarantee agreement with the Seoul Guarantee Insurance Co., Ltd. for the purchase of insurance coverage amounting to KRW 367,200,000, and the insurance period from January 1, 2004 to August 31, 2012. At that time, the Seoul Guarantee Insurance Co., Ltd and four other persons jointly and severally guaranteed the Plaintiff’s obligation under the above guarantee agreement with the Seoul Guarantee Insurance Co., Ltd.

C The Seoul Guarantee Insurance Co., Ltd. created a pledge on his deposit claim (hereinafter referred to as “instant deposit claim”) as a security for the said joint and several surety obligation.

On April 1, 2012, the Plaintiff entered into a contract with Seoul Guarantee Insurance to extend the term of the said guarantee agreement to August 31, 2014, and to increase the purchase price of insurance to KRW 504,580,000, and around that time, the Plaintiff and four other parties jointly and severally guaranteed the obligation owed by the Plaintiff to Seoul Guarantee Insurance according to the said modified contract.

In December 9, 2013, Sungju-gun filed a claim for insurance money with the Seoul Guarantee Insurance on the ground that the Plaintiff failed to implement the restoration work on gathering earth and rocks from Sungju-gun. Seoul Guarantee Insurance paid KRW 504,580,000 insurance money to Sung-gun, and collected KRW 390,062,600 by exercising a pledge on the instant deposit claim, which is a joint and several surety of the Plaintiff, on December 9, 2013.

The agreement between the Plaintiff and the Defendant regarding the recovery of mountainous districts was made in order to collect earth and rocks (hereinafter “the collection of earth and rocks in this case”) by January 2, 2013, but the shortage of funds after the completion of the collection of earth and rocks.