If you get caught with weed in Japan, you are looking at up to five years in prison, a detention process that can hold you for 23 days before you are even charged, and, if you are not Japanese, deportation followed by a functionally permanent ban on returning. Japan’s Cannabis Control Act makes no allowance for small amounts or personal use, and a revision that took effect in December 2024 made cannabis use itself a standalone crime for the first time.
The Prison Sentence and Fine
Simple possession, receipt, or transfer of cannabis carries up to five years in prison under the Cannabis Control Act.1Japanese Law Translation. Cannabis Control Act Using cannabis now carries the same maximum, closing a long-standing gap in the statute that had criminalized possession but not consumption.2Sage Journals. How Has Japan’s Cannabis Control Act Been Amended? If prosecutors prove the offense was for profit, the ceiling rises to seven years and a fine of up to ¥2,000,000 (roughly $13,000 USD). Attempts are punishable under the same provisions.
There is no minimum quantity. Japanese police have arrested people for as little as 0.019 grams. A trace on rolling papers is treated the same as a baggie.
What the First 23 Days Look Like
Police can hold a suspect for up to 48 hours without charges. If they want to continue, they transfer the case to a prosecutor, who has 24 hours to request a detention order from a judge.3U.S. Embassy & Consulates in Japan. Arrest Procedures: The First 72 Hours A judge who grants the order sets an initial ten-day detention period, and the prosecutor can request up to ten more days.4Supreme Court of Japan. Questions and Answers on Criminal Procedure The total time you can sit in custody before any formal charge is 23 days.
Japan does not allow lawyers to be present during police or prosecutorial interrogations.5Japan Federation of Bar Associations. Counsel’s Presence at Interrogation Changes the Criminal Justice You are questioned alone, sometimes for hours, and Japan’s own bar association has described the right to remain silent as “difficult” to exercise in practice. Some interrogations are recorded; the requirement is not universal.
Ask for the Duty Attorney Immediately
Japan has a duty attorney system, and this is the single most useful thing to know going in. At the police station, say “please call the duty attorney” (toban bengoshi). The station will contact the local bar association, and a lawyer will visit you in the holding cell. The first visit is free.6Japan Federation of Bar Associations. If You are Arrested! – About Duty Attorney System The duty attorney can explain your rights, outline what to expect, and contact your family. The visit is private, with no police present.
Bail Is Rare and Conviction Is Near-Certain
There is no bail before indictment. After indictment, bail is rarely granted to foreign nationals, especially those without established residence in Japan.7Government of Canada. An Overview of the Criminal Law System in Japan A tourist or short-term resident will almost certainly stay in custody through the whole process.
Japan’s conviction rate sits above 99%. Prosecutors are selective about which cases they bring forward, and once a case reaches trial, acquittals are extraordinarily rare. If physical evidence of cannabis exists, the practical chance of beating the charge is close to zero.
Deportation and the Permanent Entry Ban
For foreign nationals, the prison sentence is not the end. A conviction for any drug offense, including minor possession, triggers deportation once the sentence is served. The Immigration Control and Refugee Recognition Act then lists anyone convicted of a narcotics-related offense as inadmissible to Japan, regardless of severity.8Japanese Law Translation. Immigration Control and Refugee Recognition Act
The ban is functionally permanent. There is no cooling-off period in the statute and no automatic restoration of eligibility after a set number of years. Even if a former convict later obtains a Certificate of Eligibility through a Japanese employer or school, immigration can still refuse entry at the border. Approval is discretionary, and for drug offenses, it is not routinely granted.
The same statute reaches further than many visitors expect. It covers convictions under the laws of any country relating to narcotics, cannabis, opium, stimulants, or psychotropic substances.8Japanese Law Translation. Immigration Control and Refugee Recognition Act A cannabis conviction from your home country can be grounds for Japan to deny you entry even if you have never set foot in the country before.
CBD, Foreign Prescriptions, and Prior Use
A few boundary situations trip up visitors, and silence on them invites bad assumptions.
CBD is not automatically safe. Some CBD products are legal in Japan, but the THC tolerance is far stricter than in the United States or Europe. The 0.3% hemp threshold that the U.S. uses does not apply. Japanese regulations require THC to be essentially undetectable, with proposed limits as low as 0.001% for oils and lower still for edibles and beverages. A product sold legally in the U.S. can easily exceed Japanese limits. If you travel with CBD, get a certificate of analysis from the manufacturer confirming the product meets Japanese standards, not just the ones at home. When in doubt, leave it. Customs treats a THC violation the same as any other cannabis offense.
Foreign medical cannabis prescriptions carry no weight. Japan does not recognize them, there is no waiver process, and no amount of documentation from a foreign doctor will make a cannabis product legal to bring in. The Narcotics Control Department, which handles personal importation of certain controlled medicines, offers no pathway for cannabis.9Narcotics Control Department. Application Guidance Bringing a cannabis product in on a foreign prescription is treated as drug importation.
Cannabis used legally abroad can still create exposure. The Cannabis Control Act applies extraterritorially to Japanese nationals, so a Japanese citizen who used cannabis legally in Colorado could, in theory, be prosecuted at home; enforcement is rare because proof is hard. For foreign tourists, Japan does not routinely drug test at the border. If you come to police attention for another reason and a test comes back positive, the new use offense can apply. The practical risk from use weeks before arrival is low, but it is not zero.
What Your Embassy Can and Cannot Do
Americans sometimes assume the embassy will get them out. It will not. U.S. consular officers are prohibited by federal regulation from acting as attorneys, agents, or fiduciaries for citizens abroad, and embassy staff do not provide legal advice.10U.S. Embassy & Consulates in Japan. Arrest of a U.S. Citizen
What the embassy can do is provide a list of English-speaking attorneys organized by consular district, covering Tokyo, Sapporo, Nagoya, Osaka-Kobe, Fukuoka, and Naha.11U.S. Embassy & Consulates in Japan. Legal Assistance It can also refer citizens to Houterasu, Japan’s nationwide legal support center. Embassy staff will work to ensure Americans are treated in accordance with Japanese law, and that is the ceiling of their authority. They cannot intervene in the judicial process, pay legal fees, or negotiate with prosecutors. Citizens of other countries should contact their own embassy or consulate, which will generally face similar limits.