1. All appeals filed by the Plaintiff (Counterclaim Defendant) against the principal lawsuit and counterclaim are dismissed.

2. The costs of appeal shall be principal lawsuit and counterclaim.

1. The reasons for the court's explanation concerning this case are as follows: "entry" in the second part of the second part of the part of the second part of the part of the part of the 6th judgment of the court of first instance (which is the ground for recognition); "this court" in the part of the 2 through 3 of the 6th part of the 6th part of the 6th part of the 6th part (which is the ground for recognition); "a construction office" in the third part of the 3th part of the 6th part of the 6th part (which is the ground for recognition); "a construction office" in the part of the 4th part of the 12th part to 11; "a construction office" shall be read as "a construction office"; and the part of the 12th part to 4th part of the 11th part (which is the ground for recognition) as the reasons for the judgment of the court of first instance

[A] In a real estate sales contract which is a contract for the simultaneous performance (1) concurrent performance relationship with a real estate sales contract, the buyer's obligation to pay the remainder and seller's obligation to deliver documents for transfer of ownership are concurrently performed (see, e.g., Supreme Court Decision 92Da5713, Jul. 14, 1992). In a case where both obligations are jointly performed in a bilateral contract, even if one of the other parties' obligation becomes due, the other party's obligation is not liable for delay of performance even if the other party's obligation is not performed until the other party's obligation is performed. Such effect does not necessarily result in the exercise of the right of defense for simultaneous performance (see, e.g., Supreme Court Decision 97Da54604, 54611, Mar. 13, 1998).