(b) Whether a seller may cancel a sales contract and seek implementation of the procedure for the registration of cancellation of a transfer of ownership as a restitution to the purchaser, where the seller has made a registration of transfer of ownership by filing a lawsuit or telephone settlement procedure under the agreement to pay the remainder at the same time, unlike the agreement that the buyer has to pay the remainder in the name of a direct purchaser for the

B. Although Party A purchased real estate from Party B and Party B but did not complete the registration of ownership transfer, Party B agreed to sell the real estate to Party B at the time of completing the registration of ownership transfer through the procedure for filing a lawsuit and telephone settlement in the future Party B, and Party B filed an application for the telephone settlement against Party B and completed the registration of ownership transfer based on the relevant protocol of settlement, even if Party B’s registration of ownership transfer was made by the contract between Party B and Party B and the agreement on the omission of interim registration between Party B, if Party B’s obligation under the contract of sale and purchase is fully performed by completing the registration of ownership transfer, and Party B’s obligation is not paid to Party A even after the completion of the registration of ownership transfer, unlike the initial agreement.

According to the reasoning of the judgment of the court below and the judgment of the court of first instance as cited by the court below, since the plaintiff purchased the above real estate from the non-party on January 20 of the same year, but did not complete the registration of ownership transfer, 30,000 won shall be sold to the defendants on the date of contract, and 120,000 won shall be the intermediate payment, 148,800,000 won shall be paid to the plaintiff on April 5 of the same year, and since the above 30,000 won shall not be paid to the non-party (the non-party)'s claim for cancellation of the registration of ownership transfer under the above 30,00,000 won shall be paid to the plaintiff on the ground that the above 19,000 won shall not be paid to the non-party (the non-party)'s claim for cancellation of the registration of ownership transfer under the above 19,000,000 won shall not be paid to the plaintiff on the ground that the above 3-party's claim for cancellation of ownership transfer.

However, if the registration of ownership transfer of real estate was made through the execution of the protocol of settlement of lawsuit, the assertion or defense based on the grounds that the above lawsuit could have been submitted before the above lawsuit was made is interrupted by res judicata, and thus, it is not allowed to make any assertion contrary to the contents of the above protocol of settlement of lawsuit on such grounds. However, even if the plaintiff's obligation under the sales contract of this case was made through the contract of this case and the agreement on the omission of interim registration between the plaintiff and the defendants, even if the registration of ownership transfer was made by the above non-party and the defendants, it is not in conflict with the res judicata effect effect effect effect effect effect effect of the above contract of this case and the plaintiff's obligation under the contract of this case cannot be cancelled as a direct cancellation of the registration of ownership transfer, if the plaintiff's obligation under the above contract of this case was completed by the agreement of this case and the agreement on the omission of interim registration was not made by the contract of this case to the plaintiff.

Therefore, the court below should have deliberated further on whether the sales contract of this case was lawfully rescinded after the filing of the above lawsuit, as alleged by the plaintiff, and should have judged the propriety of the plaintiff's main claim of this case after the year when the plaintiff exercised his right to ask for the cancellation of the above transfer of ownership, which is the effect of the cancellation of the contract, on the ground that the plaintiff's primary claim of this case was included in the plaintiff's right to ask for the cancellation of the above transfer of ownership, as a contracting party, in the primary claim of this case, which is the plaintiff by subrogation of the above non-party who is the original owner. However, the court below should have judged the propriety of the plaintiff's primary claim of this case in this case, which goes against the res judicata effect of the above lawsuit telephone, and it erred in the misapprehension of legal principles as to the duty to restore due to res judicata effect or the cancellation of the contract.

Therefore, the judgment of the court below is reversed and the case is remanded to the court below for further proceedings consistent with this Opinion. It is so decided as per Disposition by the assent of all participating Justices.

Justices Park Jong-ho (Presiding Justice)