Is Night-Time Collection of the Suspect's Notebook Unlawful?

Night-time collection of the suspect's notebook is a practice in which a police station detention facility takes the suspect's notebook away from a suspect or defendant before bedtime and keeps it under police control until the next morning. Because the suspect's notebook is treated as part of the meetings with defense counsel and is protected by the right to confidential communication with counsel, taking it away without a concrete necessity can be found unlawful. Our office represented a defendant who was subjected to this practice at a police station in Tokyo. We filed repeated applications asking that the place of detention be changed to a detention house, and on October 26, 2026, the defendant was transferred to the Tokyo Detention House.

What is the suspect's notebook, and why is it protected?

Answer: The suspect's notebook (hishasha nōto) is a form prepared by the Japan Federation of Bar Associations in which the person writes down what happened in interrogations and what was discussed with the defense lawyer. It is treated as part of the meetings with counsel and is protected by the right to confidential communication with counsel.

A person in custody may, with defense counsel, "have an interview without any official being present, and may send or receive documents or articles" (Code of Criminal Procedure, Article 39(1) (刑事訴訟法39条1項)). The Supreme Court has held that this provision "can be said to derive from the guarantee of the Constitution" (Supreme Court, Grand Bench, judgment of March 24, 1999 (最大判平成11年3月24日民集53巻3号514頁)).

On the suspect's notebook, the Nagoya High Court held as follows.

"The suspect's notebook is a document in which a detained suspect writes down the content of interrogations, questions, opinions and the like in preparation for meetings with defense counsel, or writes down the content of those meetings. As the court below explained, it supplements, or forms a single whole with, the oral communication during the meeting, and therefore it cannot be treated in the same way as the suspect's other belongings." (Nagoya High Court, judgment of February 15, 2022 (名古屋高判令和4年2月15日判時2559号27頁)) (translation by our office)

The same applies to the notes of a defendant after indictment. The Osaka High Court held that "notes in which a defendant has written down the content of meetings and their defense plans" "should, in principle, be kept secret from the investigating authorities" (Osaka High Court, judgment of April 22, 2016 (大阪高判平成28年4月22日判時2315号61頁)).

Why is it a problem just to have the notebook taken away at night?

Answer: Whether or not the contents are read, the mere fact that the notebook is in the hands of police officers makes the person hesitate to write in it. That chilling effect is itself an infringement of rights.

The Yokohama District Court stated that "if there is a possibility that the content of the suspect's notebook will become known to police officers, a chilling effect arises in which the suspect refrains from writing in the notebook out of concern for this, and there is a risk that communication with defense counsel, such as the suspect providing necessary and sufficient information to counsel and receiving advice from counsel, will be obstructed" (Yokohama District Court, judgment of March 3, 2023 (横浜地判令和5年3月3日判時2593号73頁)).

In a case where detention officers took a suspect's notebook away for about 15 to 20 minutes without saying where it was, the Sapporo District Court found that it had not been shown that the notebook was read, but nevertheless held as follows and ordered Hokkaido Prefecture to pay compensation.

"Although there is no evidence sufficient to find that the detention officers or the investigators read the suspect's notebook, from Plaintiff A's point of view it is natural to fear that the detention officers or investigators were reading what was written in it. The chilling effect on Plaintiff A's forming of his will as to whether to make statements, including remaining silent, cannot be denied, and in that sense the taking away of the notebook is found to have infringed Plaintiff A's right to remain silent." (Sapporo District Court, judgment of December 3, 2024, Case No. 2021 (Wa) 2595 (札幌地判令和6年12月3日・令和3年(ワ)第2595号))

If taking the notebook away for less than 20 minutes is unlawful, a practice of taking it away every night from before bedtime until the next morning is an even heavier restriction.

Does the police explanation, "it is a dangerous item" or "it is the rule", hold up?

Answer: In our view, it does not. An abstract risk is not enough; there must be a showing of a substantial probability of a concrete problem in relation to that particular person.

On restrictions of the freedom of unconvicted detainees, the Supreme Court held that "it is not sufficient that there is merely a general, abstract risk"; there must be, under the specific circumstances, "a substantial probability that a hindrance will arise to a degree that cannot be left as it is", and the restriction "should stay within the necessary and reasonable scope" (Supreme Court, Grand Bench, judgment of June 22, 1983 (最大判昭和58年6月22日民集37巻5号793頁)). For restrictions affecting meetings with defense counsel, one court has required an even higher standard of "concrete and high necessity" (Osaka District Court, judgment of April 20, 2023 (大阪地判令和5年4月20日判タ1525号127頁)).

Police explanation	Main points of the counterargument
It could become a dangerous item (risk of suicide or self-harm)	Paper such as letter paper may be kept in the cell. The Sapporo District Court also said it is "hard to see" how paper would increase the risk of suicide or escape
Personal belongings in custody go into the storage locker at night (Article 195 of the Act on Penal Detention Facilities and the Treatment of Inmates and Detainees (刑事収容施設及び被収容者等の処遇に関する法律195条))	That Article only permits "restrictions necessary for management and operation". As the Nagoya High Court held, the suspect's notebook cannot be treated in the same way as other belongings
It is for sleeping time, or to prevent noise	Sleeping hours are set as starting at 9 p.m. (National Public Safety Commission regulations, Article 3, item 2 (国家公安委員会関係規則3条2号)). Collecting the notebook at 8 p.m. cannot be explained this way
We put it in a locker in front of you and lock it	The police hold the key. The Kumamoto Bar Association also stated that this explanation does not justify the practice
All police stations in the prefecture do the same	The very fact that the practice is uniform shows that no individual, case-by-case assessment is being made

There are also milder ways to deal with any concern. The notebook can be checked in front of the person without looking at its contents. It can be kept at night in a place where the person can see it. The detention facility has the authority to give instructions on daily life and conduct (Act on Penal Detention Facilities and the Treatment of Inmates and Detainees, Article 211(3)). There is no reason to choose the strongest restriction, which is taking the notebook away.

How does the treatment differ between a detention house and a police station detention facility?

Answer: In detention houses run by the Ministry of Justice, the rule is that personal belongings in custody are kept inside the cell. When unconvicted defendants in the same position have different conditions for preparing their defense depending on the chance matter of where they are held, this raises an issue under the principle of equality (Constitution of Japan, Article 14(1) (日本国憲法14条1項)).

Item	Detention house (penal institution, Ministry of Justice)	Police station detention facility
Where personal belongings in custody are kept	As a rule, in storage inside the cell (Ministry of Justice directive (法務省矯成第3342号依命通達))	Some facilities collect them at night and put them in a storage locker outside the cell
Who manages them	Prison officers of the Ministry of Justice	Police officers (the same organization as the investigators)
Requirements for self-supplied articles	Act on Penal Detention Facilities and the Treatment of Inmates and Detainees, Article 41	Same Act, Article 187 (almost identical requirements)
Rule after indictment	Detention house is the rule (Asahikawa District Court, decision of September 8, 1972 (旭川地決昭和47年9月8日判タ285号253頁))	Special reasons are needed to continue holding the person there

Have courts changed the place of detention?

Answer: Yes. In Kumamoto, at least 3 changes of the place of detention on the ground that the suspect's notebook had been taken away have been reported, and in the Tokyo case handled by our office, the defendant was also moved to the Tokyo Detention House.

Date	Place and procedure	Details
November 6, 2025	Kumamoto Summary Court (suspect detained at Kumamoto Kita-Kōshi Police Station)	Upon an application asking the court to use its own authority on the ground of collection before bedtime, the court heard the prosecutor's opinion and changed the place of detention on its own authority. The suspect was moved to another facility the next day (Kumamoto Bar Association president's statement; Kyodo News)
March 2026	Kumamoto Summary Court	The court allowed a change of the place of detention for a suspect whose notebook had been collected in the same way (Kyodo News)
2026 (late July or later)	Kumamoto District Court (suspect detained at the detention facility of the prefectural police headquarters)	In a case where a notebook with "Please do not collect this" written on its cover was collected, the court designated Kumamoto Prison as the place of detention (Kyodo News)
September to October 2026	Tokyo District Court (defendant detained at a police station in Tokyo); handled by our office	We documented 5 consecutive nights of collection and filed a quasi-appeal and a written request for the court to act on its own authority. The quasi-appeal was dismissed, but we continued with a special appeal, and on October 26 the defendant was transferred to the Tokyo Detention House

Each of the Kumamoto cases was handled by a different defense lawyer. In Saga Prefecture as well, a statement of the Saga Bar Association revealed a case in which Tosu Police Station collected a notebook at night on the ground that "the suspect might swallow the notebook", and pointed out that the practice has become routine at other detention facilities in the prefecture (president's statement of February 24, 2026).

What did our office do in the Tokyo case?

Answer: We asked the client to make a request and keep a record every night, used 5 days of letters as supporting material, and directly sought a change of the place of detention. When our request was rejected once, we continued with further procedures, and this led to the transfer to the detention house.

The client was a defendant who, even after indictment, was still detained in the detention facility of a police station in Tokyo. The client had remained silent throughout the investigation and had been writing down the content of meetings with defense counsel in the suspect's notebook.

1. Requests and records every night: From September 23 to 27, 2026, at around 8 p.m. every day, the client said, "I want to keep the notebook with me in my cell because there is a risk of infringing my right to confidential communication with counsel." The answers changed from day to day: "because it is a dangerous item", "because it could possibly become a dangerous item", "because there is no need". No concrete problem was ever shown. The client reported this to us by letter every day.
2. Quasi-appeal and written request (September 30): On the same day, we filed a quasi-appeal seeking to set aside the part of the decision that designated the police station detention facility as the place of detention, and a written request asking the court to order a transfer on its own authority. Our main arguments were the risk of infringing the right to confidential communication with counsel and the right to remain silent, the standard set by the 1983 Grand Bench judgment, the difference in treatment compared with detention houses (Constitution, Article 14(1)), and the Kumamoto precedents. Because the contents of the suspect's notebook are themselves confidential, we submitted only its cover to the court.
3. Special appeal (October): On October 1, the quasi-appeal was dismissed. We did not stop there, and filed a special appeal to the Supreme Court.
4. Transfer to the detention house (October 26): The defendant was transferred to the Tokyo Detention House. The defendant is now out of an environment where the notebook was taken away every night, and can prepare for trial in a place where a large volume of case records can be studied calmly.
5. Extending this to the other defendants (same day): The other defendants in the same case are still held at police stations. Since there is no reason for only some people in the same position to remain in police detention, on the same day we filed an application, based on the principle of equality, seeking the transfer of all the other defendants to the Tokyo Detention House.

Within the scope of what has been notified to our office, we have not been able to identify which procedure produced the decision to transfer. However, we believe that taking the next step each time we were turned down, and building up the facts one by one, is what changed the outcome.

What should the family or the detained person do if the notebook is taken away?

Answer: Do not hand it over in silence. Each time, say that you want to keep it with you, and write down the answer. Then pass this on to the defense lawyer.

1. State your wish every time: Say, "The content of my meetings with my lawyer is written in this, so I want to keep it in my cell." Another method is to write "Please do not collect this" on the cover of the notebook.
2. Record the answer and the reason: Write down the date and time, the officer's words and the reason exactly as given. If the reason changes, that in itself is evidence that the practice is being applied uniformly.
3. Tell your lawyer by letter or at a visit: A dated letter can be submitted to the court as it is.
4. The lawyer chooses the procedure: An application asking the court to use its own authority to change the place of detention (transfer), a quasi-appeal against the part of the decision designating the place of detention, a complaint to the detention facility, or a claim for state compensation.

Frequently asked questions

Is it unlawful for the police to take my suspect's notebook away at night?

Taking the notebook away against the person's will without any concrete necessity may infringe the right to confidential communication with counsel and the right to remain silent, and can be found unlawful. In its judgment of December 3, 2024, the Sapporo District Court found an infringement of the right to meet and communicate with counsel even where the notebook was taken away for only about 15 to 20 minutes.

Can I challenge the explanation that the notebook is a dangerous item?

Yes. Detainees are allowed to keep paper such as letter paper in their cells, so there is little reason to treat the notebook alone as a dangerous item. The Sapporo District Court also said it is hard to see how paper would increase the risk of suicide or escape.

How can the collection be stopped?

The detained person should say each time that they wish to keep the notebook, and write down the answer and the reason given. The defense lawyer can ask the judge to use their authority to change the place of detention to a detention house, or file a quasi-appeal, and can also consider a complaint to the facility and a claim for state compensation.

Has a court ever changed the place of detention because the notebook was taken away?

Yes. According to news reports, the Kumamoto Summary Court in November 2025 and March 2026, and the Kumamoto District Court in 2026, changed the place of detention on the ground that the suspect's notebook had been taken away. In the Tokyo case handled by our office, the defendant was also transferred to the Tokyo Detention House.

Can I keep my suspect's notebook with me at night in a detention house?

A Ministry of Justice directive provides that, in penal institutions, personal belongings in custody are as a rule kept in storage inside the cell. The very fact that treatment differs depending on whether a person is held in a detention house or a police station detention facility raises an issue under the principle of equality.

Can I consult you if a foreign family member has been detained?

Yes. For Chinese, our in-house Chinese interpreter or a PRC-qualified lawyer accompanies the lawyer to the visit; for other languages, an interpreter is arranged depending on the case. We visit police stations throughout Japan. We also accept consultations via WeChat (ID: matsumura1119).

Our office's main track record

Our office starts from the concrete disadvantage our client has suffered, and even where case law or established practice is unfavorable, we have challenged it directly by going back to the purpose of the statute, its legislative history and the principles of the Constitution.

• Relief from false stalking accusations: In a case concerning a written warning under Article 4(1) of the Anti-Stalking Act (ストーカー規制法4条1項), the Osaka High Court, in a judgment of June 26, 2024 (大阪高判令和6年6月26日), recognized the legal effect of the warning and showed a path to judicial relief. The judgment was published in Hanrei Chihō Jichi (判例地方自治) and has been discussed in Hōgaku Kyōshitsu (法学教室), Shakai Shirin (社会志林) and Hōsei Kenkyū (法政研究).
• Relief from false accusations of facilitating illegal employment: We have challenged cases in which employers and foreign nationals who were not at fault faced deportation, and the question of whether punitive adverse administrative measures require intent or negligence has also been taken up in administrative law scholarship.
• Obtaining special permission to stay in Japan
• Withdrawal of unlawful administrative measures
• Obtaining an acquittal (partial acquittal)
• Treatment issues in police detention facilities: We have filed complaints and protests concerning the reading of suspects' notebooks, refusal to send letters addressed to defense counsel and notices of appointment of defense counsel, and refusal to accept books sent in by defense counsel.

Media reports and articles on our cases are collected on our Media and Publications page (Japanese), and the full text of our defense policy is available at "Defense Policy of Attorney Daisuke Matsumura: Breathing Life into the Law" (note, Japanese).

Legal provisions and sources

• Constitution of Japan, Articles 14(1), 34 and 38(1) (日本国憲法14条1項、34条、38条1項)
• Code of Criminal Procedure, Articles 39(1) and 429(1)(ii) (刑事訴訟法39条1項、429条1項2号) (e-Gov Laws and Regulations Search, Japanese)
• Act on Penal Detention Facilities and the Treatment of Inmates and Detainees, Articles 31, 41, 187, 195, 210(2) and 211(3) (刑事収容施設及び被収容者等の処遇に関する法律31条、41条、187条、195条、210条2項、211条3項) (e-Gov Laws and Regulations Search, Japanese)
• Supreme Court, Grand Bench, judgment of June 22, 1983 (最大判昭和58年6月22日民集37巻5号793頁); Supreme Court, Grand Bench, judgment of March 24, 1999 (最大判平成11年3月24日民集53巻3号514頁); Supreme Court, Third Petty Bench, decision of April 12, 1995 (最三小決平成7年4月12日刑集49巻4号609頁)
• Nagoya High Court, judgment of February 15, 2022 (名古屋高判令和4年2月15日判時2559号27頁); Yokohama District Court, judgment of March 3, 2023 (横浜地判令和5年3月3日判時2593号73頁); Sapporo District Court, judgment of December 3, 2024 (札幌地判令和6年12月3日・令和3年(ワ)第2595号); Osaka High Court, judgment of April 22, 2016 (大阪高判平成28年4月22日判時2315号61頁); Osaka District Court, judgment of April 20, 2023 (大阪地判令和5年4月20日判タ1525号127頁); Asahikawa District Court, decision of September 8, 1972 (旭川地決昭和47年9月8日判タ285号253頁)
• Kumamoto Bar Association, president's statement (November 21, 2025) (熊本県弁護士会会長声明); Saga Bar Association, president's statement (February 24, 2026) (佐賀県弁護士会会長声明)
• Kyodo News, "Suspect's notebook improperly collected? Kumamoto Summary Court orders change of detention facility" (共同通信「被疑者ノート、不当回収か　熊本簡裁が留置場変更決定」) (November 12, 2025); Kyodo News, "Kumamoto District Court also orders change of detention place over prefectural police's collection of suspect's notebooks" (同「熊本地裁も勾留先変更決定　県警の被疑者ノート回収で」) (September 24, 2026); Kumamoto Asahi Broadcasting (KAB), "Police collect 'suspect's notebooks' before bedtime: what is the problem?" (Japanese) (November 12, 2025)

Related articles

• Where is my arrested family member? How to find the place of detention (Japanese)
• When to consult a lawyer about a foreign national's criminal case, and how to choose one (Japanese)
• Criminal cases involving foreign nationals (feature, Japanese)
• Case results (Japanese)
• Other languages: 日本語 / 简体中文 / 繁體中文 / 한국어 / Tiếng Việt

Author: Daisuke Matsumura, Attorney at Law (Dai-Ichi Tokyo Bar Association, Reg. No. 59077), Funado International Law Office / Last updated: October 26, 2026

This article provides general information and does not guarantee the outcome of any individual case. Some facts of the cases introduced here have been generalized so that clients cannot be identified.