Marijuana in Japan: what is allowed and what are the consequences (2026)

Japan has recently made what appears to be a shift in regulations between laws, resulting in a complete overhaul of the entire system. Cannabis has ceased to have its own criminal law and has been included in the general law on narcotics.

The consequences are twofold and go in opposite directions: the mere use has become punishable, while at the same time, the path to medical use has opened up. Below is what follows from the text of both laws.

Legal status checked on September 5, 2026, in the texts of the laws from the official Japanese government service. This is a description of the regulations, not legal advice.

Is possession of marijuana in Japan punishable?

Yes, and recently in a new place in the law, which changes more than it appears at first glance. After the reform, cannabis no longer has its own criminal law: the definition from the law on narcotics states that a narcotic is a substance from the annex and cannabis.

The former law on cannabis control has been renamed to the law on the regulation of cannabis cultivation. The name itself shows where the legislator has shifted the focus: from possession to production.

The effect is direct. Possession of cannabis is subject to the same regulation as other narcotics: anyone who unlawfully produces, distributes, sells, acquires, or possesses a narcotic other than diacetylmorphine is subject to a penalty of imprisonment for up to seven years.

Attempting is also punishable, so liability begins even before obtaining the substance. This solution is typical of Japanese criminal law, but rarely mentioned in cannabis comparisons.

Japan is therefore one of the strictest countries in this comparison, and the reform has not changed that. How it compares to other countries is shown by our map of marijuana legality.

How much marijuana is allowed in Japan?

There is no quantitative threshold, and this is not a gap in the development. The law punishes possession of a narcotic as such and differentiates only by purpose: without profit up to seven years, for profit from one to ten years, and that is the end of the entire gradation.

In the latter case, there is also a monetary penalty. Depending on the circumstances, the court may additionally impose a fine of up to three million yen, alongside the penalty of imprisonment.

Weight does not appear in the regulation at all. There is no quantity table, no reference to an executive act, and there is no concept corresponding to the European concept of a minor quantity, to which a minor act could fall.

This distinguishes Japan from most countries in this comparison, where liability is graded by weight. Here, it is graded by intent, specifically whether the act was for profit.

The practical conclusion is inconvenient for travelers. There is no amount at which possession would be treated leniently, as the regulation does not recognize the category of a minor act or any of its variations.

The intent to profit is, moreover, a qualitative concept, not a number. Its determination depends on the circumstances of the case, so the boundary between the two ranges cannot be weighed either.

What are the consequences of exceeding the threshold in Japan?

The scale is short and high. For possession, there is a penalty of up to seven years of imprisonment, and for profit from one to ten years, with a fine of up to three million yen depending on the circumstances. Both penalties may be imposed concurrently, not interchangeably.

The most important change, however, concerns use, which Japanese law previously did not punish directly. The regulation states that only a person authorized to administer narcotics may provide them, issue them for administration, or prescribe them.

Violation of this regulation is punishable by up to seven years, the same as possession. There are two exceptions: a researcher administering narcotics for research purposes and a person who received the substance from an authorized person for the purpose of administration.

Anyone who smokes outside of this path fulfills the elements of a prohibited act. This closes a gap that earlier studies cited, describing Japan as a country punishing possession but not consumption.

Cultivating cannabis without authorization has its own regulation in the second law and is punished more severely than possession: from one to ten years, and for profit from one year upwards, with a possible fine of up to five million yen.

Does Japan have a medical marijuana program?

The reform opened a path that did not exist before, and it did so somewhat incidentally, by simply moving cannabis to the law on narcotics. Since cannabis is now a narcotic, the usual Japanese prescription mechanism applies to it. Previously, cannabis stood outside this mechanism, and this path was closed.

This mechanism is simple in structure. Only a person with a separate authorization, i.e., a licensed doctor authorized to use narcotics, may provide a narcotic, issue it for administration, or prescribe it.

The patient is directly protected in this arrangement. A person who received the preparation from such a person for administration is exempt from the prohibition, so they are not liable for possession or use.

We have not checked specific allowed preparations and do not add them from secondary sources. This material describes the legal mechanism, not a list of drugs available today in Japanese pharmacies.

It is worth noting how unusual this structure is. The same legal act that introduced the criminality of mere use also opened the path to medical application, and both effects result from one change.

Is it allowed to cultivate cannabis for personal use in Japan?

Cultivation has its own law in Japan and a higher threat than possession. Anyone who cultivates cannabis without authorization is subject to a penalty of imprisonment from one to ten years, starting from a threshold that does not exist at all for possession. The regulation does not recognize the concept of home cultivation for personal use.

For profit, the ranges start from one year, with no upper time limit specified. Depending on the circumstances, there is also a fine of up to five million yen.

The name of the law after the reform sounds like a declaration of intent. It speaks of the regulation of cannabis cultivation, not of cannabis control as such, which shows where the legislator has placed the focus.

There is no threshold for the number of plants here. Liability arises from the mere fact of cultivation without authorization, regardless of the scale and to whom the harvest was intended.

For a reader accustomed to European solutions, this is a surprising reversal. In most of the countries we describe, home cultivation has a milder or equal regulation to possession, while in Japan it is clearly stricter.

Cultivation and possession thus have completely different places in the system. The former stands in the law on the regulation of cultivation, the latter in the general law on narcotics.

Frequently asked questions

Is marijuana legal in Japan?

No. After the reform, cannabis is a narcotic in the sense of the general law, and its possession is punishable by up to seven years of imprisonment. Attempting is also punishable.

Is smoking marijuana punishable in Japan?

Yes. Only a person authorized may provide a narcotic, issue it for administration, or prescribe it, and violation of this regulation is punishable by up to seven years.

How much marijuana can be possessed in Japan?

The regulation does not specify any amount. It punishes possession of a narcotic as such and differentiates liability only by purpose, not by weight. Weight does not appear in it at all.

What are the consequences of cultivating cannabis in Japan?

From one to ten years of imprisonment, and for profit from one year upwards, with a possible fine of up to five million yen. Cultivation has a separate law and is punished more severely than possession.

Does Japan have medical marijuana?

The reform opened a path through the usual prescription mechanism: only a doctor with separate authorization may prescribe a narcotic, and a patient who received the preparation is exempt from the prohibition.

What did the Japanese cannabis law reform change?

It moved cannabis to the general law on narcotics and renamed the former law on cannabis control to the law on the regulation of cultivation. The result is the criminality of mere use and the opening of the medical path.

Sources

This article is for informational and educational purposes and does not constitute legal advice. The legal status described in the article is valid as of the date of publication: regulations regarding cannabis may change. Before making a decision, consult a lawyer or current legal acts.

Author: Michał Waluk