Why Non-Prosecution Is the Only Complete Exit in a Drug Case: Building a Defence Strategy for Foreign Nationals

If a member of your family is in custody over a drug case and you are about to choose a lawyer, there is one thing we would say first. In Japanese criminal practice, securing a suspended sentence tends to be treated as a good result. In a foreign national's drug case, that yardstick does not transfer. Because of how Article 24, item 4, sub-item (chi) (入管法24条4号チ) is constructed, the bare fact of having been convicted becomes a ground for deportation (退去強制). This article explains, provision by provision, why a non-prosecution decision (不起訴処分) obtained before charges are filed is the only complete exit that leaves your residence intact.

Key points

• Article 24(4)(chi) makes a person convicted of violating drug legislation deportable, and does not ask how heavy the sentence was.
• The exclusion for suspended sentences sits in the proviso to sub-item (ri); sub-item (chi) has no proviso.
• So even a suspended sentence at trial leaves the defence incomplete when measured against residence.
• Only a non-prosecution decision obtained before charges are filed ends the case with the status of residence (在留資格) intact.
• In case charges are nevertheless brought, the second and third lines of defence, the deportation process and special permission to stay (在留特別許可), have to be designed in parallel.

Why is non-prosecution the only complete exit in a drug case?

Here is the conclusion first. In a drug case, the moment a conviction is entered, the person becomes deportable whatever their status of residence. The basis is Article 24(4)(chi), which makes subject to deportation anyone convicted of violating the Narcotics and Psychotropics Control Act, the Act on Regulation of Cultivation of Cannabis Plants, the Opium Act, the Stimulants Control Act, the Narcotics Special Provisions Act, or Part II, Chapter 14 of the Penal Code.

What makes the provision unusual is that it says nothing whatever about the type or the length of the sentence. A fine, a remission of punishment (刑の免除), a suspended sentence: each is caught equally, because each follows a conviction. Conversely, a non-prosecution decision is not a conviction, so it never reaches the threshold of the provision at all. That is what gives a non-prosecution outcome its decisive significance.

• Sub-item (chi) lists six statutes: the Narcotics and Psychotropics Control Act, the Act on Regulation of Cultivation of Cannabis Plants, the Opium Act, the Stimulants Control Act, the Narcotics Special Provisions Act, and Part II, Chapter 14 of the Penal Code
• There is no limit by type or length of sentence, so fines, remission of punishment and suspended sentences are all included
• Appendix I (別表第一) work and student statuses, and Appendix II (別表第二) permanent resident, long-term resident and spouse of a Japanese national statuses, are caught alike

Surely a suspended sentence protects my residence?

We understand entirely why people want to believe this, and the misunderstanding is widespread. But given how the provisions are built, it does not hold for drug cases.

The relief for suspended sentences is written into Article 24(4)(ri). That sub-item makes deportable a person sentenced to life imprisonment or to imprisonment (拘禁刑, the unified custodial sentence introduced in June 2025) exceeding one year, and its proviso then removes, among others, those whose sentence has been suspended in whole. But the same sub-item opens with the words: in addition to those listed in (ni) through (chi). A drug case falling under sub-item (chi) therefore sits outside the territory of sub-item (ri) from the beginning, and the benefit of that proviso does not reach it.

A Japanese defendant who receives a suspended sentence walks out and rebuilds within the community. A foreign national who receives the identical sentence finds that a separate process is only just beginning. Facing that gap squarely is where strategy begins.

The idea of three lines of defence

That said, a non-prosecution decision cannot always be obtained. When we take on a foreign national's drug case, we design it in three tiers from the very first detention visit.

The order matters. Finishing at the first line is the best outcome, and that is where we put our effort. But betting everything on the first line and neglecting the rest is dangerous. What the client said in the criminal process, which issues were contested, and what material was gathered all become the foundation of the arguments made later before the immigration authorities. Conversely, admitting facts too readily on the criminal side leaves the second and third lines thin from the outset.

• First line: a non-prosecution decision in the criminal case (elements of the offence, intent, lawfulness of evidence gathering)
• Second line: contesting whether the ground for deportation is made out in the deportation process
• Third line: special permission to stay (building the factors in Article 50(5) and arguing equality on the basis of published cases)

What does defence counsel build up before the charging decision?

The period before the prosecutor decides on a disposition is limited, and how much can be assembled within it makes a large difference to the outcome.

The effect on residence in particular has to be communicated deliberately, because the prosecutor in charge cannot be assumed to have the structure of Article 24(4)(chi) in mind. That a conviction gives rise to a ground for deportation regardless of the weight of the sentence; that the foundation of the person's life is here; that there are family members they support: all of this is shown concretely, with the provisions and with documents. The material that can influence the exercise of discretion comes out of this patient work.

• Examination of the facts (whether possession was known, the relationship with co-defendants, the lawfulness of investigative procedures)
• Securing a person to take responsibility for the client and setting out concretely how they will supervise
• Medical attendance and steps taken to prevent relapse
• Material on the continuation of employment or study
• A written opinion showing, by reference to the provisions, the gravity of losing a status of residence

The decisive stage differs by offence

According to the 2024 White Paper on Crime (drawing on the Annual Report of Statistics on Prosecution), the prosecution rate for Cannabis Control Act violations is 44.1 per cent and the suspension of prosecution rate is 35.5 per cent. For Stimulants Control Act violations, by contrast, the prosecution rate is 74.2 per cent and the suspension of prosecution rate only 8.5 per cent. For Narcotics Control Act violations the figures are 57.5 per cent and 15.9 per cent, and for Narcotics Special Provisions Act violations 36.8 per cent and 52.5 per cent. Across all special-law offences other than Road Traffic Act violations, the suspension of prosecution rate is 45.5 per cent.

What the numbers suggest is that in cannabis cases suspension of prosecution is a realistic option, while in stimulant cases the opening is considerably narrower. These are aggregate figures by offence, however, and they do not distinguish between a first offence and a repeat one, or between simple possession and possession for the purpose of profit. Because the outlook turns on the individual circumstances, we do not use figures as a substitute for a conclusion.

About our office

At Funado International Law Office, attorney Daisuke Matsumura handles every stage personally, from the first detention visit through to the close of trial. We do not operate on a basis where clerks or junior lawyers attend detention visits in his place. In a drug case, where judgments have to be made one after another in the short time before the disposition, it matters that the person who knows the details is the same person acting from beginning to end.

For Chinese, a dedicated interpreter experienced in cases involving foreign nationals is on staff. Alongside the interpreter appointed by the investigating authorities, you have an interpreter working for you throughout the criminal process. For languages other than Chinese, we arrange an interpreter to suit the case. Renewals and changes of status of residence after the criminal process are handled together with an affiliated administrative scrivener.

From matters we have handled

We obtained an acquittal for a client prosecuted under the Stimulants Control Act for possession for the purpose of profit, after exhaustive analysis of the evidence and sustained work on questioning of the defendant and cross-examination. We have also handled a large number of cases tried before lay judge panels and serious cases that attracted media coverage.

In a matter where a client was treated as a collector in a specialised fraud case and re-arrested several times, careful handling of the interrogations and formal objections to improper questioning produced non-prosecution decisions on every count. In the case of a woman wrongly accused of promoting illegal employment, we are continuing to litigate a challenge to the established practice under which intent and negligence are treated as unnecessary for grounds for deportation, and in that same case we obtained special permission to stay, which was without precedent.

What is at stake in a drug case is not only the weight of a sentence but the life you have built in Japan. Set the objective early, build towards it in the right order, and a way forward opens up. Please note that this article is general commentary only; for your own situation, speak to a lawyer directly. Past matters turned on their own particular facts, and they 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