Social System

Yoko Sato

Consent of Victim and Criminal Penalty

Yoko Sato , Associate Professor

Graduate School of Law (Law Course, School of Law)

High school : Oita Uenogaoka High School

Academic background : Graduate School of Law, Hokkaido University

Research areas
Criminal Law
Research keywords
criminal law, consent of victim, consent of patient, right of self-determination, euthanasia

What kind of discipline is Criminal Law?

The penal code is generally defined as the “law concerning crimes and punishments.” Namely, the law establishes what constitutes crimes and how the crimes shall be punished (upper and lower limits of punishment). The discipline of Criminal Law is broadly divided into two fields. One is Criminal Law interpretation, which interprets provisions of the Penal Code considering various aspects, including protection of interests worth protecting by law, maintenance of social order, and the protection of the human rights of criminal actors. Because laws need to respond to a fluid society, provisions cannot make stipulations in such detail that everything is clear just by reading them. However, because criminal laws have an effect on the human rights of criminal actors in the form of punishment, the range of their punishment should be always obvious from their provisions. Otherwise it would be unpredictable what kind of act would be punished and when, which would infringe your liberty. This is why interpretation designed for interpreting provisions is important. The other field is Basic Criminal Jurisprudence that includes Philosophy of Criminal Law, Criminal Law History, Comparative Criminal Law, Criminology and Penology, which together form the foundation of Interpretation. This is an important field of basic academic studies that provide a principle of interpretation. I specialize in Interpretation based on Comparative Criminal Law and mainly study the theme of “consent of victim.”

My book on consent of victim 


What kind of research are you doing?

“Consent of victim” is about the question of whether there is a crime when the victim consented to the violation of their legal interest (injury, confinement, property damage, etc.). Precedents and theories in Japan widely recognize that consent of victim has an effect to negate the crime. For example, when you are on a train, you are in a state of confinement where you cannot get off the train, but you consented to such state of confinement by boarding the train. Consequently, the driver of the train is rightly not charged with the confinement (If a passenger who found that he was on a wrong train exclaimed, “Stop the train now before reaching the next stop and let me get off!,” there would be no negation of crime due to consent of victim. Of course there has been no dispute that the case does not constitute a crime, but there are disputes on the ground to negate the crime.) However, consent to homicide (a request by an individual for another to murder them) does not negate the crime. This is because Article 202 of the Penal Code provides “A person who kills another at the other's request or with other's consent, shall be punished by imprisonment with or without work for not less than 6 months but not more than 7 years.” (However, the statutory penalty is lighter than that for other homicides.) Precedents and theories recognize that consent to bodily injury may not negate a crime according to circumstances. For example, in a case where a person caused a rear-end accident with consent of the driver to commit insurance fraud which resulted in injury to the driver, the judgment of the case affirmed the criminal offence of bodily injury stating that the court would determine whether the consent had an effect to negate the crime “in light of the motive and purpose to obtain the consent, means, method, site and degree of bodily injury and various other circumstances” (Ruling of the Supreme Court on November 13, 1980, Criminal Casebook Volume 34, No. 6, pg. 396.) The court thought that consent aimed at committing a crime such as fraud did not negate the crime. However, many theories maintain that it is not important whether or not the consent is aimed at committing a crime but the point is the severity of the injury. They think that acts that cause injuries putting lives at risk are not allowed based on Article 202 of the Penal Code.

Why does consent of victim negate a crime? In what cases does consent negate a crime and in what cases does it not? For example, if a person killed another person with whom he is having an illicit love affair after obtaining her consent by saying, “We cannot be united in this world. Let us become one in the afterworld,” to end their adulterous relationship but without intention to kill himself (disguised double suicide), is there consent of the victim? If there is the consent of the victim, Article 202 applies, whereas there is not, simple homicide (Article 199) applies. The issue is about conditions to make consent effective. I am studying the issue as well.


What is your next goal?

Consent of victim is deeply connected with patient consent regarding medical treatment. Injections, operations, and other forms of treatment are likely to bring positive effects on human body, but sometimes might lead to bad results. Injections and operations are themselves consequential interventions to the human body. Therefore, it is generally believed that treatment requires patient consent. However, is it necessary to punish treatment actions conducted with an accepted method but without consent of the patient (called peremptory treatment) on a charge of bodily injury? Are physicians not allowed to treat those who attempt suicide who refuse to get treatment? Thinking this way I find some difference between patient consent for treatment and consent of victim. What do they have in common and what is the difference between them? Is patient consent a mandatory requirement to avoid punishment related to treatment issues? I am now studying these issues.



(1) Yoko Sato, Consent of Victim ? Reconstruction based on Several Crime Discussion (Higaisha no sh?daku : kakuronteki k?satsu ni yoru saik?sei) Seibundoh (2011)
(2) Saku Machino, Patients’ Right to Self-determination and Law (Kanja no jiko ketteiken to hou) T?ky? Daigaku Shuppankai (1986)