Japan's Cannabis Use Offence: 2025 Arrests and What Courts Impose

Those figures describe who ends up in the system. Most are young, as the police breakdown reported by Nikkei shows below. In a police survey of 1,006 people arrested for possession or use in November and December 2025, more than 40% of those in their twenties or younger had connected with dealers online, mostly through X and other social media and encrypted messaging apps.

Which cannabis offences exist in Japan?

Since December 12, 2024, cannabis has been a narcotic under the Narcotics and Psychotropics Control Law, and cultivation falls under the renamed Act on Regulation of Cannabis Plant Cultivation. The maximums below match the statutes as summarised by the Atom Law Office, a criminal-defence firm.

Before the reform, simple possession carried up to five years and use was not an offence at all, which meant a positive urine test alone could not lead to charges. That gap was the main reason the health ministry pushed the change.

How is use proved?

By urine testing. The Atom Law Office explains that investigators look for THC-COOH, a metabolite the body produces after THC is consumed, which helps separate active use from passive exposure to smoke.

What do first offenders usually get?

Prison is the exception for a first, small-quantity case, but a criminal record is common. The Atom Law Office says that in its own caseload of 44 cases about 32% ended without prosecution, and about 90% of first offenders who were convicted received a suspended sentence. Those are one firm's figures, not national statistics, and outcomes depend on quantity, intent to sell and prior record.

• Quantity and packaging — small bags and scales point to supply and to the for-profit tier.
• Prior drug record — repeat offenders are far less likely to get a suspended sentence.
• Online purchase trail — messages with sellers are routinely examined, according to the police data reported by Nikkei.

CBD products can trigger the same charges

A CBD product with Δ9-THC above the legal residue limit counts as a narcotic. MHLW and prefectures named five such products between May 2025 and April 2026, including gummies, a drink and waxes, and asked owners to hand them in. See the entries in our Red List before buying CBD in Japan.

The national figures for 2026 will come out in spring 2027. Until then, the 2025 data are the best measure of how hard the use offence is being enforced. This is general information, not legal advice; anyone contacted by police should ask for a lawyer at once.