A. On August 18, 2014, the Plaintiff entered into a technical service contract (a contract amount: KRW 180 million; value-added tax separate) for various urban planning facilities, such as roads, parks, etc. with respect to the construction of new apartment units (hereinafter “original construction”), and entered into a technical service contract for conversion, etc. of a mountainous district (a contract amount: KRW 20 million; value-added tax separate); on June 2015, the Plaintiff entered into a separate contract for the construction of a new apartment unit (hereinafter “GGGG”) for civil engineering design (a contract amount: KRW 40 million; KRW 20 million; value-added tax separately); and on April 2016, each contract for the construction of a new apartment unit (hereinafter “GGGGG”) with respect to each construction of a new apartment unit (hereinafter “construction project”).

B. On February 16, 2017, the Plaintiff and the Defendant agreed with the Plaintiff that “each design service (including additional service) relating to the Changwon Construction and Kimhae Construction has been completed as a result of the task that had been performed up to the present, and that, in the case of design service costs, the intermediate payment that the Plaintiff received and the Defendant shall settle that the Plaintiff would pay an additional design service cost of KRW 50 million (excluding value-added tax) as the additional design service cost, and that the Plaintiff will not be held liable for civil or criminal liability later (hereinafter “instant agreement”).

C. On May 8, 2017, the Plaintiff sent to the Defendant a content-certified mail stating that “the payment of the settlement amount according to the agreement is demanded.” On May 12, 2017, the Defendant notified the Plaintiff on May 12, 2017 that “the Plaintiff would immediately pay the settlement amount upon the arrival of the payment period.”

On January 24, 2018, the Plaintiff sent to the Defendant a content-certified mail stating that “the payment of the settlement amount according to the agreement is demanded.” On January 26, 2018, the Defendant sent to the Plaintiff a content-certified mail stating that “on January 26, 2018, the Plaintiff would receive the service cost upon completion of the structural construction, and receive the service cost immediately.”

[Ground for recognition] A.