1. The plaintiff's appeal is dismissed.

2. Of the appeal costs, the part pertaining to the participation in the appeal is the intervenor joining the Plaintiff.

1. Basic facts

A. The Plaintiff is an insurer who has concluded an automobile insurance contract with the Plaintiff’s Intervenor regarding the automobile (hereinafter “Plaintiff’s vehicle”), and the Defendant is the insurer who has concluded an automobile insurance contract with respect to the vehicle E (hereinafter “Defendant”).

B. On March 1, 2019, around 13:23, the instant accident occurred where the Plaintiff’s vehicle and Defendant’s vehicle face on the front road of Songpa-gu Seoul Metropolitan Government.

C. On April 16, 2019, the Plaintiff paid KRW 5,290,00,000 calculated by subtracting KRW 500,00 of the Plaintiff’s self-charges from the repair cost of KRW 5,790,00,00 for the insurance proceeds from the instant accident.

The Plaintiff filed an application for deliberation and coordination of the instant accident with the G Deliberation Committee (hereinafter referred to as the “Deliberation Committee”).

On July 22, 2019, the Deliberation Committee rendered a decision that the ratio of responsibility between the Plaintiff’s vehicle and the Defendant’s vehicle to KRW 10% and KRW 90% (hereinafter “instant decision”) was finalized.

E. On September 25, 2019, the Plaintiff filed the instant lawsuit after the instant decision became final and conclusive.

[Ground of recognition] Facts without dispute, entries in Gap evidence 1 to 7 and the purport of the whole pleadings

2. Determination

A. The plaintiff asserts that since the accident of this case entirely occurred by the negligence of the driver of the defendant vehicle, the defendant is obligated to pay the plaintiff the indemnity amount of KRW 5,290,000 and the damages for delay.

The defendant asserts that there was an agreement to file a lawsuit or a compromise contract according to the decision of this case, and the driver of the plaintiff vehicle was negligent.

B. Even if a decision of the deliberative committee on the resolution of adjustment under the mutual agreement on the deliberation of claims for reimbursement of automobile insurance becomes final and conclusive through certain procedures, it is difficult to view that there is an agreement to file a lawsuit. However, in a case where the decision of adjustment is finalized as above, an agreement between the parties as to the disposition of mediation is established, and such agreement constitutes a settlement agreement under the Civil Act, barr