불공정한 법률행위에 기한 급부의 반환청구 가부

Majority opinion about a return claim of a benefit according to an Unfair Juristic Act is that the Unfair Juristic Act is deemed null and void and its following benefits do not have any legal cause, as it violates good customs and other social orders. This corresponds to the payment due to an illegal cause, so the return claim of benefits is not permitted, and such illegal cause only exists for the beneficiary who gained a significantly larger profit, so only the victim is permitted to claim for a return. In view of many precedents, some cases are applied a broad sense to the Unfair Juristic Act and if they can be divided into the fair partsand beyond the fair parts which correspond to the excessive profiteering by one side, only latter part is admitted as the partial nullity and the remaining part except the partial nullity is validity. At this time, the victim can claim a return of the benefit corresponding to the partial nullity. Other cases are applied Article 104 of the Civil Code to the unfair juristic act and admit that the entire act is deemed null and void. Even in these cases, both profiteers and victims are permitted to claim for a return. There exists minority who support the conclusion of precedents. In the view of several cases of legislation and precedents, the writer supports to interpret this case as follows. The essential of the Unfair Juristic Act is that one person gained significantly high benefit than the other and based on the benefit which profiteer gave; there exists two parts which are the equivalent exchange part and the excessiveprofit part by one side. The former part is not antisocial and only the latter part is antisocial, which means the former part is not correspond to the payment due to an illegal cause. Thus, it is permitted that the both profiteer and victim can claim for a return of benefits corresponding to the former part in accordance with the Civil code Article 741. The excessive profit part is applicable to the payment due to an illegal cause under the Civil code Article 746, however, the illegal cause is only by the profiteer so the victim is permitted to claim for a return of benefit corresponding to this part under the proviso of the Civil code Article 746.