(1) The understanding of acquisitive crime is related with the understanding of a form of action and violation of the benefit and protection of the law. The effective conditions for the understanding related with a form of action are obtained from the documents of the general requirements with the aspect of facts. Therefore, it is unnecessary to be expressed to the outside. Even tough there was a consent by mistake, it shall be valid. In addition, it is not a property owner but the person with a right to cancel the occupation of property who has a right of understanding. However, fraud and extortion require a grant. A person who has a right to dispose the property even though he/she is the possessor can grant the property. For understanding which excludes theft, it is necessary to be able to recognize that an object is free from its own control. Even a child or psycho can be aware of the loss of the control on an object, which can be applied to robbery as well. Fraud and extortion are a transfer of property to the counter party. This kind of grant should also be understood as it is. In case of understanding associated with the violation of the benefit and protection of the law, it is the property owner only who can have the right of understanding. The understanding of the property owner means an understanding on giving up the benefit and protection of the law, not understanding of facts. Therefore, a party of understanding should be well aware of the value of the benefits and protection of the law and the effects of acceptance in order to dispose of them based on a free will. For this, both excellent perception and decision skills on giving up the benefits and protection of the law are required. The understanding on the violation of the benefit and protection of the law requires a public announcement. The property owner`s consent is an understanding on the violation of the benefits and protection of the law. Therefore, general theories can be applied to the investigation on effectiveness. If a mistake is found in relations of the benefits and protection of the law, the content shall be void. In fraud as well, consent shall be unenforceable if there is a mistake associated with the benefits and protection of the law. Because the consent is valid in case of a mistake which is unrelated with the benefits and protection of the law, however, the requirements for fraud can be excluded. The consent by force without a free will shall be void as well. (2) In a property damage crime, it can be interpreted that the requirements are met even though it was committed under a victim`s consent. Therefore, the understanding associated with a form of action is meaningless. However, if a property owner agrees with the violation of the value of his/her property, it can be interpreted that he/she has given up the legal protection on the property. In addition, it is reasonable to conclude that the requirements for the property damage crime are not met. Therefore, a victim`s consent in a property damage crime is related with the violation of the benefits and protection of the law. Hence, a person who can have a right to agree upon the violation of the benefit and protection of the law is the property owner. In a property damage crime in terms of consent ability, a victim`s consent is related with the violation of the benefits and protection of the law. Therefore, it is the same with the property owner`s consent in the acquisitive crime. Unlike an acquisitive crime, however, even though the consent is later canceled, it could not be restored if the property is completely destroyed in a property damage crime. If it is impossible to restore, it is necessary to limit the consent ability more strictly than the acquisitive crime to protect those who have poor judgment such as minors. In addition, minors` consent ability should be judged based on individual case, not by age.