Multiple Offenses in Japan: How Are They Treated? From Concurrent Crimes to Continuing Offenses

When an individual's conduct results in the violation of multiple criminal statutes, or when a series of related actions could each be seen as a separate crime, legal systems must have a framework to determine how these multiple offenses are counted and punished. This area of law, known in Japan as Sūzai Ron (罪数論)—the theory of the number of crimes—is crucial for ensuring proportionate punishment and upholding principles like the prohibition of double jeopardy. Japanese criminal law categorizes situations involving multiple offenses into several distinct types, each with its own rules for determining liability and sentencing. These include apparent plurality (conflict of laws), inclusive single offenses, offenses treated as one for sentencing purposes, and true plurality (aggregate crimes).

1. Is It One Crime or Many? The Initial Determination

The first step in Sūzai Ron is to determine whether a given course of conduct constitutes a single crime or multiple distinct crimes. While various theoretical criteria have been proposed (e.g., based on the number of acts, the number of criminal intents, or the number of legal interests infringed), the prevailing approach in Japan often looks to the number of times the constituent elements (kōsei yōken) of a specific statutory offense are fulfilled. However, this initial count can be modified by doctrines that either consolidate apparent multiple offenses into one or treat closely related distinct offenses in a unified manner for sentencing. The ultimate goal is to avoid unfairly punishing an individual multiple times for what is essentially a single criminal enterprise while ensuring that all distinct aspects of their wrongdoing are adequately addressed.

2. Apparent Plurality – Conflict of Laws (法条競合, Hōjō Kyōgō)

Sometimes, a single criminal act appears to fall under the definitions of multiple criminal statutes simultaneously. This situation is termed Hōjō Kyōgō (法条競合), or conflict of laws (literally, "competition of statutory provisions"). In such cases, it is understood that only one of these statutes should ultimately apply, and the conduct is treated as a single offense under that one applicable provision. This is not a case of multiple crimes being committed, but rather one crime that could technically be described by several laws. The principles used to resolve which statute applies include:

• Special Relationship (特別関係, Tokubetsu Kankei): When one statute is a special or more specific version of another general statute (e.g., an aggravated form of a basic offense, or a specific type of fraud versus general fraud). The principle lex specialis derogat legi generali (a special law derogates from a general law) applies, and the more specific statute is used. For example, the old Penal Code had a provision for parricide, which was a special law relative to the general law of homicide.
• Supplementary Relationship (補充関係, Hojū Kankei): When one statute is designed to apply only if another, more primary statute, does not (e.g., arson of non-inhabited structures might be supplementary to arson of inhabited structures; if the structure is inhabited, the latter, more serious offense applies). Similarly, a consummated crime will typically take precedence over an attempt or preparation for that same crime if they are part of the same continuous course of conduct.
• Alternative/Intersecting Relationship (択一関係/交差関係, Takuitsu Kankei/Kōsa Kankei): When the definitions of two statutes partially overlap, applying to the same conduct under certain circumstances. Courts will interpret which statute is more appropriate or intended to cover the specific situation, often prioritizing the graver offense or the one that more precisely captures the essence of the wrongdoing.

In all cases of Hōjō Kyōgō, the result is that the defendant is convicted and sentenced for only one offense.

3. Substantive Unity – Inclusive Single Offense (包括一罪, Hōkatsu Ichizai)

An Inclusive Single Offense (包括一罪, Hōkatsu Ichizai) arises when multiple acts, or acts resulting in multiple infringements of legal interests, are nevertheless treated by law as constituting a single, unified crime for the purposes of conviction and sentencing. This typically occurs when the multiple acts are so closely connected in time, manner, or criminal purpose, or when they target the same overarching legal interest in a continuous fashion, that they are considered to form one criminal transaction or episode. The underlying idea is often a combination of a perceived unity in the protected legal interest and a unity (or close connection) in the criminal conduct.

Hōkatsu Ichizai can be further categorized:

A. Absorbed Offenses (吸収一罪, Kyūshū Ichizai)

This occurs when a less serious criminal act is considered an integral part of, or typically accompanies, a more serious offense, and is thus "absorbed" into the graver crime, not leading to a separate conviction.

• Concomitant Acts (随伴行為, Zuihan Kōi): Minor offenses that are typical byproducts or accompanying features of a more serious crime may be absorbed. For example, minor property damage caused during the commission of a murder (e.g., breaking a door to enter) might be absorbed into the homicide charge, as the penalty for murder is considered sufficient to cover such incidental damage.
• Co-punished Prior/Subsequent Acts (共罰的事前行為/共罰的事後行為, Kyōbatsu-teki Jizen/Jigo Kōi):
  • Prior Acts: Preparatory acts are generally absorbed into the consummated crime if it is completed (e.g., illegal possession of a weapon used in a robbery is absorbed into the robbery conviction).
  • Subsequent Acts: Minor acts committed after the principal offense to secure the fruits of the crime or conceal it may sometimes be absorbed if they don't involve a new, distinct infringement of a legal interest. For instance, the initial judicial view on a subsequent embezzlement of already embezzled funds was that it was absorbed. However, the Supreme Court, in a ruling on April 23, 2003, revised this, holding that a subsequent act of embezzlement concerning the same property could constitute a new offense if it represented a fresh criminal resolve and act, especially if the manner of holding or the purpose changed significantly.

B. Narrowly Defined Inclusive Offenses (狭義の包括一罪, Kyōgi no Hōkatsu Ichizai)

These are situations where the nature of the crime itself encompasses a series of acts or a continuing state.

• Connecting Offenses (接続犯, Setsuzoku-han): A series of acts committed in close temporal and spatial proximity, often against the same victim and legal interest, may be treated as a single connecting offense. For example, striking a victim multiple times in rapid succession during a single assault episode would typically be treated as one count of assault or injury, not multiple counts for each blow. The Supreme Court (ruling of July 23, 1949) treated stealing items from the same warehouse over a short period in several trips as a single theft.
• Collective Offenses (集合犯, Shūgō-han): Certain offenses by their nature involve or presuppose a course of conduct or multiple similar acts.
  • Habitual Crimes: For example, habitual gambling (常習賭博罪, jōshū tobaku-zai). Multiple instances of gambling by a person with a recognized gambling habit are typically consolidated into a single charge of habitual gambling (Supreme Court ruling, April 10, 1951).
  • Occupational Crimes: Running an unlicensed business over a period usually constitutes a single offense of operating that business without a license, rather than multiple offenses for each day of operation or each transaction.
• Continuing Offenses (継続犯, Keizoku-han) vs. State Offenses (状態犯, Jōtai-han): This distinction is crucial for understanding the duration and unity of certain crimes.
  • Continuing Offense: The criminal act creates an unlawful state that persists over time, and the crime is considered ongoing as long as this unlawful state is maintained by the offender. Unlawful confinement (逮捕監禁罪, taiho kankin-zai) is a classic example; the crime continues as long as the victim is confined. This has implications for the statute of limitations (which starts running from the end of the confinement) and for when accomplices can join the crime.
  • State Offense: The crime is completed and terminates as soon as the unlawful state is initially brought about, even if the effects or the unlawful condition of property persist. Theft is a typical example; the crime is complete when the property is taken, even though the thief continues to possess it unlawfully. The subsequent possession is a consequence, not a continuation of the theft itself.

4. Procedural Unity for Sentencing: Offense Treated as One for Sentencing (科刑上一罪, Kakei-jō Ichizai)

Even when multiple distinct crimes are technically committed, Japanese law (Penal Code Article 54) provides that they may be treated as a single offense for sentencing purposes (Kakei-jō Ichizai) if they are very closely connected. In such cases, the offender is punished according to the statutory penalty for the gravest of the offenses involved. This acknowledges a closer link than Heigōzai (aggregate crimes, see below) but recognizes that distinct legal provisions have been violated. This category is also treated as a single crime for the purposes of double jeopardy (ichiji fusairi). There are two main types:

A. Ideological Concurrence / Ideal Concurrence (観念的競合, Kannen-teki Kyōgō)

This occurs when "a single act infringes two or more penal provisions" (Penal Code, Article 54, Paragraph 1, first part).

• "One Act": The determination of what constitutes "one act" is not based solely on a single physical movement but on a broader social understanding of the conduct as a unified behavioral unit. The Supreme Court (ruling of May 29, 1974) established this social perspective.
• Examples:
  • A single instance of driving under the influence of alcohol by a person who also does not possess a valid driver's license would constitute both drunk driving and unlicensed driving. These are treated as being in ideological concurrence (Supreme Court ruling, May 29, 1974).
  • A single punch that simultaneously constitutes assault against Person A and, due to its public nature, public indecency (if, for example, it causes an indecent exposure).

B. Connected/Instrumental Offenses (牽連犯, Kenren-han)

This occurs when "a crime is committed as a means to another crime, or a crime is committed as a result of another crime, and such means or result infringes another penal provision" (Penal Code, Article 54, Paragraph 1, latter part).

• Inherent Connection: For Kenren-han to apply, there must be an inherent, typical, and necessary connection between the crimes as means and end, or cause and effect. A merely coincidental or opportunistic link is not sufficient. The Supreme Court (ruling of December 21, 1949) emphasized this need for a typical instrumental relationship.
• Examples:
  • Unlawfully entering a residence (trespass) as a means to commit theft or robbery therein.
  • Forging a document (forgery) as a means to commit fraud by using that document.

5. True Plurality: Aggregate Crimes (併合罪, Heigōzai)

When an offender has committed two or more distinct crimes that do not fall into any of the above categories of substantive or procedural unity, and for which no final and binding judgment has yet been rendered, these crimes are treated as Aggregate Crimes (併合罪, Heigōzai) under Article 45 of the Penal Code.

• Sentencing for Aggregate Crimes: Japanese law has specific rules for calculating the sentence for Heigōzai (Articles 46-51, Penal Code). These rules aim to create a consolidated sentence that reflects the overall criminality but is less than the simple sum of all possible maximum penalties.
  • For multiple terms of imprisonment, the maximum term of the gravest offense can be increased by up to one-half, but this total cannot exceed the sum of the maximum terms of all individual offenses (Article 47).
  • If one of the crimes is punishable by death or life imprisonment, other penalties are generally not imposed (absorption), though fines and confiscation can still be added (Article 46).

6. Complex Scenarios and Business Implications

The doctrines governing the number of crimes can become quite complex in practice.

• The "Clasp Phenomenon" (かすがい現象, Kasugai Genshō): This refers to a situation where Crime X might link Crime A and Crime B, which would otherwise be Heigōzai. If X is in ideological concurrence (or instrumental connection) with A, and also separately with B, courts have sometimes treated all three (A, X, and B) as a single Kakei-jō Ichizai (e.g., Supreme Court ruling, May 6, 1958; Supreme Court ruling, May 27, 1954).
• Complicity and Number of Crimes: Generally, the number of offenses for which an instigator or aider is liable follows the number of crimes committed by the principal. However, if a single act of instigation or aiding facilitates multiple distinct crimes by the principal, this may be treated as ideological concurrence for the accomplice (Supreme Court ruling, February 17, 1982). For joint principals who together commit multiple criminal acts leading to multiple harms, this usually results in multiple instances of joint principalship, treated as Heigōzai (Supreme Court ruling, February 16, 1978).

Business Crime Examples:

• Conflict of Laws: A specific industry regulation imposing a penalty for certain conduct might take precedence over a more general Penal Code offense if both are technically applicable.
• Inclusive Single Offense: A series of small embezzlements from the same corporate account by an employee over a period, driven by a single ongoing intent, might be treated as one comprehensive act of embezzlement. A continuous, unauthorized discharge of pollutants from a factory over several days could be seen as a single environmental offense (keizoku-han).
• Ideological Concurrence: A single act of submitting a deliberately falsified financial statement to authorities could simultaneously violate corporate reporting laws, tax laws, and potentially constitute fraud against investors.
• Connected Offenses: Forging a key contract (means) to secure a fraudulent loan (end); illegally accessing a computer system (means) to steal trade secrets (end).
• Aggregate Crimes: An executive who engages in insider trading (a financial crime) and also commits tax evasion on the profits from that trading (a separate tax crime) would likely face these as aggregate crimes. Bribery often involves multiple payments; depending on whether they are seen as fulfilling a single corrupt agreement or multiple distinct agreements, they could be treated as an inclusive single offense or aggregate crimes.

Conclusion

The Japanese legal framework for addressing multiple offenses (Sūzai Ron) is a complex but structured system designed to ensure that criminal conduct is appropriately identified and punished, avoiding both undue leniency and unfair multiple punishments for what is essentially unified criminal behavior. The categorization of offenses—as truly single, inclusively single, treated as single for sentencing, or as genuinely multiple (aggregate) crimes—has profound practical consequences for charging decisions, trial procedures (including double jeopardy considerations), and, most significantly, the final sentence imposed. For businesses and their legal advisors, understanding these distinctions is vital when assessing the potential scope of liability arising from any course of conduct that might trigger multiple legal violations.