1. The plaintiff's appeal is dismissed.

2. The costs of appeal shall be borne by the Plaintiff.

The purport of the claim and appeal is the purport of the appeal.

1. Determination as to the cause of claim

A. The plaintiff asserted that the plaintiff paid 245,833 won per month to the defendant for 48 months, in addition to the monthly salary, according to the agreement with the defendant on the division of retirement allowances. If the payment of the paid money is not recognized as retirement allowances, the plaintiff would incur damages equivalent to the above money by paying the defendant the money in the name of the retirement allowances without any legal ground, while the defendant would gain profits equivalent to the above amount. Thus, the defendant is obligated to return the money in the name of the above retirement allowances to the plaintiff as unjust enrichment.

B. It is reasonable from the perspective of fairness to view that an employer should return to the employer the money in the name of the retirement allowance received by the employee as unjust enrichment, if the validity of the payment of the paid retirement allowance is not recognized, even though the employer actually paid the money in the name of the retirement allowance to the employee.

However, considering the legislative intent of the retirement allowance system as mandatory law, the above legal principle can only be applied on the premise that there is an actual retirement allowance installment agreement between an employer and an employee.

Therefore, even though the pertinent agreement entered into between an employer and an employee is merely a determination of the wage, if the employer only takes the form of a retirement allowance installment agreement to evade the payment of retirement allowances, such legal doctrine cannot be applied.

In other words, there is an agreement between the employer and the employee that the employee should not pay a separate retirement allowance at the time of retirement, including a monthly or daily retirement allowance, as well as ② the amount of money in the name of the retirement allowance distinct from the wage is specified, ③ the amount of the wage, other than that of the above retirement allowance, includes the retirement allowance division agreement.