1. The Defendants are jointly and severally liable to the Plaintiff for KRW 33.6 million, and 5% per annum from August 31, 2010 to April 9, 2015.

According to the overall purport of Gap evidence Nos. 1, 5, 6, and 7, the plaintiff was awarded a contract on March 17, 2009 with the defendants and C as the price of KRW 19,630,000 for the installation of facilities for the high-tech LPG charging station operated by them, and on June 30, 2009 for the scheduled completion date. The plaintiff completed the construction after the completion date. The plaintiff prepared a contract modification agreement with the defendants and C after the completion date, which changes the scheduled completion date on February 20, 2010 to "the scheduled completion date on August 30, 2010." Thus, barring special circumstances, the defendants are jointly and severally obligated to pay the construction price of KRW 360,000,000,000 for the above construction price of KRW 16,000,000,000,000,000,000,000.

(On the other hand, the plaintiff asserted that he completed the construction work on June 30, 2009 and claimed for the payment of damages for delay from the next day. However, according to the above contract amendment agreement, the scheduled date of completion has been changed on August 30, 2010 in sequence, and accordingly, the deadline for the payment of the construction cost has been extended. However, there is no evidence to prove that the plaintiff had been delayed before August 31, 2010. Accordingly, the plaintiff's claim for damages for delay is without merit. As to this, the defendants asserted that C, who operated D, was liable for the payment of the construction cost independently, was signed only by signing the construction contract. However, there is no evidence to support this fact, even if it is recognized, since the defendants cannot be exempted from the obligations in relation to the plaintiff, the above assertion by the defendants is without merit.

Therefore, the Defendants jointly and severally with C shall pay the construction cost of KRW 33.6 million to the Plaintiff.