This Court includes the Plaintiff (Counterclaim Defendant)’s principal claim and the Defendant (Counterclaim Plaintiff)’s counterclaim that was added by this Court.

1. Basic facts

A. F, the owner of ten households for the 4th apartment building on the instant land (hereinafter “instant building”) in the state of not having been registered, Pyeongtaek-si Cze-si, 286.3 square meters (hereinafter “instant land”) and ten households for the 4th apartment building on the instant land (hereinafter “instant building”), completed the registration of ownership transfer in the Plaintiff’s name, which was made on December 1, 2015, No. 79408, which was received on November 30, 2015, for the instant land, and completed the registration of ownership transfer in the Plaintiff’s name, which was made on November 30, 2015. The registration of ownership transfer was completed on December 21, 2015, with each Suwon District Court’s receipt of No. 94188, Dec. 21, 2015, under the name of the Plaintiff on December 21, 2015.

(B) The registration of site ownership was completed for the instant land on the same day, and the registration of site ownership transfer in the Plaintiff’s name for the instant bank room (hereinafter “instant registration of site ownership”).

원고, F 및 E은 2016. 1. 29. 투자계약서(작성일자 2016. 1. 10.)를 공증인가 법무법인 M 등부 제2016년 제114호로 인증하였는데(이하 ‘이 사건 인증서’라고 한다), 그 주요 내용은'㉠ 이 사건 토지 및 건물의 가치를 1,250,000,000원으로 인정하고, ㉡ 원고의 F에 대한 채권(300,000,000원), E의 F에 대한 채권(200,000,000원)으로 투자금 지급에 갈음하고, F의 투자금은 250,000,000원으로 인정하여 그 투자비율을 3(원고):2(E):2.5(F)로 하며, ㉢ 이 사건 토지 및 건물의 소유권은 원고의 명의로 하되, 원고는 이를 임의로 처분할 수 없고, 기존 근저당권(근저당권자 G조합, 채권최고액 650,000,000원)의 채무자를 원고로 변경하며, ㉣ 이 사건 토지 및 건물의 관리, 처분에 관한 사항은 당사자들이 협의하여 결정하되, 이를 제3자에게 임대함에 있어서는 원고가 위 당사자를 대표하여 임대차계약을 체결하고 그 대금을 수령할...