Investigated for Stimulant Use in Japan (Article 41-3): Urine Analysis, Personal-Use Cases and Your Right to Stay

In personal-use stimulant cases, nothing may have been seized, and the process moves forward on a single piece of material: the urine analysis. Clients often describe the days passing without any clear sense of what has actually been proved, until they find they have been charged. For foreign nationals there is a second track running alongside the criminal case, namely how to protect the status of residence (在留資格). This article sets out the provision and penalty for the use offence, the nature of urine analysis as evidence, and the consequences for residence, from a practitioner's standpoint.

Key points

• Use of stimulants carries imprisonment for up to 10 years under article 41-3(1)(i) of the Stimulants Control Act.
• National Police Agency figures for 2025 record 3,742 arrests for use among stimulant offences, with a repeat offender rate of 64.6 per cent.
• In personal-use cases the urine analysis is in practice the only objective evidence, so the sampling procedure and the identity of the sample are matters to examine.
• A conviction is a ground for deportation (退去強制) under article 24, item 4, sub-item (chi) of the Immigration Control and Refugee Recognition Act (入管法24条4号チ), and the weight of the sentence is not a requirement.
• After deportation, a ground for denial of landing (上陸拒否) with no fixed time limit remains under article 5(1)(v).

Which provision covers stimulant use in Japan, and what is the penalty?

Use of stimulants is punishable under article 41-3(1)(i) of the Stimulants Control Act by imprisonment for up to 10 years. Where there was a profit-making purpose (営利目的), the penalty is imprisonment for a determinate term of not less than 1 year, with a fine of up to 5 million yen added.

Article 41-2(1), which covers possession, transfer and receipt, likewise provides for imprisonment for up to 10 years, so use and possession sit at the same level as far as the statutory range is concerned.

According to the National Police Agency's report on the organised crime situation in 2025 (final figures), arrests for stimulant offences in 2025 broken down by conduct were 3,742 for use, 2,030 for possession, 211 for transfer and 123 for smuggling. Use is the largest category.

If my urine tests positive, is there really nothing to argue about?

Many people take it that way, but the existence of a forensic result and proof that an offence was committed are, in law, different things. We would not claim that there is always room to argue; we would say that there are several matters that ought to be examined.

First, how the urine was obtained. Where it is recorded as a voluntary submission, can it really be said to have been given voluntarily? Where it was taken compulsorily, were the requirements for the warrant met? Second, the question of identity: can it be said that the sample collected and the sample analysed are the same, and can the storage and handovers be traced through the records? Third, there remains the question of probative value, that is, how much the analytical method and the result actually prove.

In some cases the lawfulness of what led to the sampling is also in issue. We cannot pronounce on the merits of any individual case, but the existence of a single forensic report is no reason to end the inquiry.

• Whether the sample can be said to have been given voluntarily, and how that process was recorded
• Where the sample was taken compulsorily, whether the requirements for the warrant were met
• Whether the identity of the collected and analysed samples, and the chain of custody, can be traced
• Whether anything was wrong in what led to the sampling: street questioning, a search of belongings, or a request to accompany officers

The question of when and where the substance was used

A difficulty peculiar to personal-use cases is identifying the date, time and place of the conduct. A urine analysis shows that the substance was present in the body; it does not directly show when or where it was taken.

The timing and place are therefore filled in by statements, and this calls for caution. A date can harden during the flow of questioning while the client's memory remains uncertain, and where an interpreter is involved, a hedge such as "probably around then" can be replaced by a categorical expression in the Japanese written statement.

Once you have signed a statement that differs from your own recollection, correcting it later is not easy. How to approach questioning is something to work out concretely with defence counsel at this stage.

Where there is a previous case of the same kind

According to the National Police Agency source cited above, the repeat offender rate for stimulant offences in 2025 was 64.6 per cent. This is a category in which people with prior convictions of the same kind form the majority, and that can be taken to influence decisions on disposition and sentence.

Where there is a previous sentence, and particularly where the new offence occurs during a period of suspension, the criminal outlook becomes harder. For a foreign client, whether the sentence is one to be served, and if so how long it is, feeds directly into the framework for special permission to stay (在留特別許可) discussed below.

At the same time, a previous sentence may indicate that a health problem, dependence, lies behind the conduct. This is not something that blaming the client will solve. Beginning, so far as circumstances allow, to attend a medical institution, to join a treatment programme and to review living arrangements has value both in the criminal process and in the immigration process that follows.

The effect on your status of residence

Article 24, item 4, sub-item (chi) of the Immigration Control and Refugee Recognition Act lists as subject to deportation persons convicted of violating the named laws, the Stimulants Control Act among them. Even where the case involves use alone, and even where nothing was seized, the fact of a conviction brings the provision into play. It contains no limitation as to the type of sentence and no proviso excluding suspended sentences.

The provision also applies whatever the type of status of residence. Holders of Appendix II (別表第二) statuses such as permanent resident (永住者) and long-term resident (定住者) stand on the same footing as holders of Appendix I (別表第一) statuses.

After deportation, a ground for denial of landing under article 5(1)(v) remains. The denial of landing based on a deportation record under article 5(1)(ix) carries fixed periods of 1 year, 5 years and 10 years, but item (v) has no such time limit. This is something we always explain at the earliest stage of a case.

Building the three lines of defence in a use case

For drug cases involving foreign nationals, our office designs the defence in three stages, and in use cases the tasks at each stage are clearly distinct.

The first line is a decision not to prosecute (不起訴処分) before charges are filed. We scrutinise the lawfulness of the urine sampling, the identity of the analysed sample and the identification of the time of use, and where issues exist we put them to the prosecutor concretely. Because sub-item (chi) requires a "conviction", stopping the case here avoids the effect on residence at its root. A strategy whose final goal is a suspended sentence at trial has set the target wrongly when measured against the right to stay.

The second line is contesting, within the deportation proceedings, whether the grounds for deportation apply at all. The third is special permission to stay. Among the factors set out in article 50(5), "conduct" and "the facts giving rise to deportation" are the greatest obstacles in use cases, so we build up continued treatment, family supervision, and stability of work and housing in documentary form. Because article 50(3) prevents an application for special permission to stay once a written deportation order has been issued, managing the sequence and the timing is essential.

Case results, and how we work with clients

The two matters below, concerning the handling of questioning and residence, are those we are able to describe publicly. Past results reflect the particular circumstances of those cases and are not a guarantee of a similar outcome.

Attorney Daisuke Matsumura personally handles every stage, from the first visit at the detention facility through to the close of trial. In use cases, how statements take shape over repeated rounds of questioning decides the outcome, so returning to the client again and again to confirm the approach is the core of the work. For Chinese we have a dedicated interpreter on staff who is experienced in cases involving foreign nationals; separate from the interpreter appointed by the investigating authorities, this interpreter works for the client and is available throughout the criminal process. For languages other than Chinese, we arrange an interpreter according to the needs of the case. Residence matters after the criminal case ends are handled together with an affiliated administrative scrivener.

• In a matter where the client was accused of acting as a collector in an organised fraud scheme and was rearrested several times, we handled each round of questioning carefully, objected to improper questioning, and built up our arguments and evidence, obtaining decisions not to prosecute on every count.
• For a client who had lost his status of residence and was arrested and prosecuted for unlawful stay, we negotiated with the authorities so that a marriage and an acknowledgment of paternity could be completed, gathered favourable evidence in a situation where almost no official documents from the country of nationality existed, and analysed the immigration authorities' past grant examples, obtaining special permission to stay on a single application.

Personal-use cases look simple from the outside, which is exactly why people conclude too quickly that there is nothing to argue. Trace carefully how the evidence was produced and how much it actually proves, and matters worth examining often remain. For a foreign client, that examination can also be the only way in to protecting the right to stay. Please do not reach a conclusion alone; take the opportunity to review the case against the record. This article is a general explanation; for your own case, consult a lawyer directly. Past results reflect the particular circumstances of those cases and are not a guarantee of a similar outcome.

This article reflects the law as at August 2026.

About the author

Daisuke Matsumura, Attorney at Law
Dai-Ichi Tokyo Bar Association (registration no. 59077, admitted 2019)
Funado International Law Office (Fuse Building Main Wing 3F, 3-4-10 Takada, Toshima-ku, Tokyo)
Practice focused on criminal defence for foreign nationals and immigration proceedings.
Results include an acquittal in a Stimulants Control Act case (possession for the purpose of profit), non-prosecution in organised fraud cases, and special permission to stay in cases regarded as difficult.

Funado International Law Office
Website: https://matsumura-lawoffice.jp/
WeChat ID: matsumura1119