1. The Defendant (Counterclaim Plaintiff) paid KRW 22,289,161 to the Plaintiff (Counterclaim Defendant) and its related amount from March 29, 2016 to May 30, 2018.

1. Basic facts

A. A. Around December 2014, the Plaintiff was promoting the construction of a new building on, and one parcel (hereinafter “instant land”). However, as a result of the design of the building, the Plaintiff introduced the “E architect office” to the Plaintiff around January 2015, the Defendant, who was aware of D, the Plaintiff’s spouse, was the Plaintiff, on the part of the existing architect office and the mind.

Around that time, F, the office leader of the plaintiff, defendant, and E architect, obtained permission for construction from the second-class multi-household house, and later, he was willing to change the construction permission to the third-class multi-household house.

B. On January 22, 2015, the Plaintiff delegated the following matters to the Defendant:

(2) All applications and requests made to the relevant persons and the competent authorities for construction sites and for the exercise of rights for the management of construction sites and for the preservation of construction sites, and ④ the exercise of rights to the owner of adjacent land in connection with construction works, and ④ the exercise of rights to the owner of adjacent land in connection with construction works, and the authority to request matters deemed necessary for the management of other construction sites and construction works.

C. Based on the design drawings drawn up by E architect office on May 1, 2015, the Plaintiff obtained a construction permit for newly constructing a second-class detached house on the instant land.

On May 15, 2015, the Plaintiff paid KRW 16,050,00 on the day to the Defendant KRW 396,550,000 on the instant land for construction of a new third-class neighborhood living facility and multi-household housing (hereinafter referred to as “instant contract”), down payment (36,050,000) and KRW 16,050,000 on the same day.

On June 22, 2015, the Plaintiff applied for permission to change the purpose of use of construction on a large scale repair basis, and obtained permission to change the new construction of four-story neighborhood living facilities and detached houses on the instant land on August 25, 2015.

under this section.