Generally, when parties and a court have done as hard as they can do, a judgement becomes final and conclusive. So the judgement has res judicata, executive power and formative power. But though a judgement is final and conclusive, this one is often out of accordance with the real existence. These judgements is called undue judgement and can not be agreed to execute. The execution of this judgement is also undue execution. The present time theories and cases approve to allow a lawsuit of demurror against claims for execution of undue judgement without the process of retrial. If the judgement have executed, also allow to claim damages, but not approve to claim unjust enrichment. In my opinion, in the case of a judgement is apparently wrong, to this judgement executive power must be denied, and might allow to claim damages and to claim unjust enrichment.
Ⅱ. 소송법상의 구제방법
Ⅲ. 실체법상의 구제수단