The appeal is dismissed.

The costs of appeal are assessed against the defendant.

The grounds of appeal are examined.

1. On the grounds of appeal Nos. 1 and 2, the lower court, based on its stated reasoning, gave specific and timely consent to the amendment of the instant benefit provision by Defendant employees’ collective decision-making method.

Nor can it be deemed that there was an implied consent or ex post facto ratification by Defendant employees, and the amendment of the instant benefit provision could not be deemed reasonable by social norms, which could have been without the consent of the said employees.

Examining the records in accordance with the relevant legal principles, the above recognition and determination by the lower court are justifiable.

In doing so, there is no error of misapprehending the legal doctrine regarding the employees’ consent by collective decision-making method or amendment of rules of employment related to retirement allowances which are reasonable by social norms, or exceeding the bounds of the principle of free evaluation of evidence in violation of logical and empirical rules

The precedent cited in the grounds of appeal is different from the case of this case, and it is not appropriate to invoke this case.

2. As to the ground of appeal No. 3, the lower court determined that, on the grounds set forth in its reasoning, even if the Plaintiff submitted a written oath to waive part of the retirement allowance before retirement, it has no effect as a waiver of the retirement allowance claim

Examining the record, the above determination by the court below is just in accordance with the relevant legal principles, and there is no error of law by misapprehending the legal principles as to the waiver of the claim for retirement allowance.

3. Therefore, the appeal is dismissed, and the costs of appeal are assessed against the losing party. It is so decided as per Disposition by the assent of all participating Justices on the bench.