Glossary of Japanese Criminal Law Terms

Introduction

Japanese criminal law draws on a vocabulary that is largely codified in the Penal Code (Keihō, 1907) and the Code of Criminal Procedure (Keiji Soshō Hō, 1948). The terms below reflect the doctrinal categories of the General Part of the Penal Code, the Special Part, and the procedural lexicon of investigation and trial.

Keihō (刑法)

Keihō — the Penal Code — is the principal criminal statute, enacted in 1907 and effective from 1908. It is organised into a General Part (Articles 1–72) and a Special Part (Articles 73–264). The General Part sets out the scope of application, the forms of punishment, the general elements of criminal liability, and the defences. The Special Part defines specific offences.

Keiji Soshō Hō (刑事訴訟法)

Keiji Soshō Hō — the Code of Criminal Procedure — was enacted in 1948, replacing the 1922 Code. It governs the stages of criminal process: investigation, indictment, trial, appeal, and execution. The Code reflects post-war American influence, particularly in its warrant requirements and the right to counsel.

Han-zai (犯罪)

Han-zai — crime — is defined by the Penal Code as conduct that satisfies the elements of a criminal offence (tekiyō), is unlawful (lacking a justification), and is culpable (the actor is blameworthy). The German-inspired three-stage structure (Tatbestand, Rechtswidrigkeit, Schuld) dominates Japanese criminal law doctrine.

Hanzaisha (犯罪者)

Hanzaisha — offender — denotes a person who has committed a crime. The term is used in both substantive (elements of liability) and procedural (rights of the accused) contexts. The Penal Code distinguishes among principals (seihan), accomplices (kyōhan), and accessories (yoketsu).

Kei (刑)

Kei — punishment — comprises the sanctions enumerated in Article 9 of the Penal Code: death penalty (shikei), imprisonment with labour (life, chōki chōeki, or fixed term, yūki chōeki), imprisonment without labour (kinko), fine (bakkin), misdemeanour detention (kōryō), and petty fine (ryōkin).

Shikei (死刑)

Shikei — the death penalty — is authorised for certain aggravated homicides under Article 199 and related provisions. It is carried out by hanging (Article 11). The number of executions has declined significantly in the 2010s and 2020s, though public opinion remains broadly supportive of the penalty.

Chōki Chōeki (長期懲役)

Chōki Chōeki — life imprisonment with labour — is the second most severe punishment. A person sentenced to life imprisonment may be eligible for parole after ten years, though in practice parole for life-sentenced prisoners is extremely rare.

Yūki Chōeki (有期懲役)

Yūki Chōeki — imprisonment with labour for a fixed term — ranges from one month to twenty years (Article 12). The term may be extended to thirty years in cases of aggravated recidivism. The prisoner is required to perform labour set by the prison administration.

Bakkin (罰金)

Bakkin — a fine — is a monetary penalty of ¥10,000 or more (Article 15). The fine is the most commonly imposed punishment. Non-payment of a fine may result in civil detention (rōeki).

Kōryō (拘留)

Kōryō — misdemeanour detention — is a short-term confinement of one to thirty days in a detention facility (Article 16). It is distinct from imprisonment and is used for minor offences such as petty theft or insult.

Ryōkin (科料)

Ryōkin — a petty fine — is a monetary penalty of ¥1,000 to ¥9,999 (Article 17). It is reserved for the most minor criminal infractions and quasi-criminal regulatory offences.

I-han (違犯)

I-han — the actus reus of the offence — is the objective element of the crime, comprising the conduct, the result, and the causal connection between them. Causation is assessed under the “reasonable foreseeability” test derived from the Supreme Court’s jurisprudence in Fukuoka Nichin-geki Jiken.

I-han no Ishi (違犯の意思)

I-han no Ishi — mens rea or criminal intent — is the subjective element of the offence. The Penal Code distinguishes between intent (kokui — the actor’s knowledge and will to commit the offence) and negligence (kashitsu). Intent may be direct (kakutei-teki) or conditional (kakutei-teki ni hairanai).

Ka-so (過失)

Ka-so — negligence — is the failure to exercise the care that a reasonable person would exercise in the circumstances. Criminal negligence is punishable only when expressly provided for in the Special Part (e.g., negligent homicide, negligent injury). The standard is objective.

Seitō Bōei (正当防衛)

Seitō Bōei — self-defence — is a justification under Article 36 of the Penal Code. An act of self-defence is not punishable if it is “(i) an urgent and unjust attack on one’s own or another’s right to life, body, liberty, or property, and (ii) the defensive act is the minimum necessary to repel the attack.” Excessive self-defence (bōei no teido o koeiru) may result in a reduced penalty or excuse.

Hijō Shiyō (緊急避難)

Hijō Shiyō — necessity — is a justification under Article 37 of the Penal Code. An act that causes harm is not punishable if it was performed to avert “an imminent danger to the life, body, liberty, or property of oneself or another” and the harm caused does not exceed the harm averted.

Seishin Shōgai (精神障害)

Seishin Shōgai — insanity or diminished capacity — is a defence under Article 39 of the Penal Code. An act committed in a state of insanity (seishin shōgai) is not punishable. An act committed in a state of diminished capacity results in a mandatory reduction of the sentence. The standard is a combination of medical (a recognised mental disorder) and legal (inability to distinguish right from wrong or to act on that understanding) criteria.

Gobyaku (誤信)

Gobyaku — mistake of fact — refers to an error concerning a factual element of the offence. Under Japanese doctrine, a reasonable mistake of fact negates intent; an unreasonable mistake may reduce the offence to a negligent variant if one exists. Mistake of law is generally no defence, though the Supreme Court has recognised limited exceptions.

Saimin (催眠)

Saimin — sleep or automatism — is a defence based on unconscious or involuntary conduct. A person who commits an act while sleepwalking or in a state of complete unconsciousness lacks the voluntariness required for criminal liability. The Penal Code does not expressly address automatism, but doctrine treats it as negating the actus reus.

Yoketsu (共犯)

Yoketsu — accomplice or accessory — is a participant in a crime who does not qualify as a joint principal (kyōhan). Article 62 of the Penal Code penalises any person who “aids a principal” in the commission of an offence. The penalty for an accessory is generally less than that for a principal.

Kyōhan (共犯)

Kyōhan — joint principal — is a person who “jointly commits” a crime with another or others (Article 60). The doctrine of joint enterprise (kyōdō seihan) holds each joint principal liable for the acts of all co-principals if the acts were within the scope of the common plan.

Han-nin (犯人)

Han-nin — suspect — refers to a person suspected of having committed a crime before indictment. The term is used throughout the pre-indictment stages of the Code of Criminal Procedure. A suspect’s rights include the right to counsel and the privilege against self-incrimination.

Hikoku (被告)

Hikoku — the accused or the defendant — is the person against whom a criminal prosecution has been initiated. The term is used from the point of indictment to the final judgment. The accused enjoys the presumption of innocence, the right to a speedy trial, and the right to examine witnesses.

Tsumi no Kyōyaku (罪の共謀)

Tsumi no Kyōyaku — conspiracy — is the agreement of two or more persons to commit a crime. The Penal Code does not generally criminalise conspiracy as a standalone offence, except in limited circumstances such as conspiracy to commit robbery (Article 208-2). The Conspiracy Act (2017) introduced a new offence of conspiracy to commit certain serious offences, but its scope is narrow.

Mimai (未遂)

Mimai — attempt — is the commencement of the commission of a crime that is not completed (Article 43). An attempt is punishable only when the Special Part expressly so provides. The penalty for an attempt may be reduced. The test for “commencement” is whether the actor has performed an act that is directly connected to the realisation of the offence.

Kanshu (教唆)

Kanshu — instigation or abetting — is inducing another person to commit a crime (Article 61). The instigator is punished as a principal. The inducement may be explicit or implicit, and the crime must actually be committed or at least attempted for the instigator to be liable.