The investigation into the Kansai branch of the ready-mix concrete industry labor union “Kan-nama” covers “incidents” in four prefectures. They are the Osaka Prefectural Police, Kyoto Prefectural Police, Shiga Prefectural Police, and Wakayama Prefectural Police in terms of police jurisdiction.

What is puzzling is that it took so long for the police to arrest the union members, turning the matter into a crime five years after the union activity in question took place. If a crime was truly suspected, it would be natural to file charges immediately.

First of all, labor union activities are guaranteed by Article 28 of the Constitution. They are not a crime. For example, in the Wakayama case, the Osaka High Court handed down a not guilty verdict in 2023 and the ruling was finalized. Presiding Judge Makoto Wada stated the following:

“The Kansai District Ready-Mixed Concrete Branch (Kan-nama) of the All Japan Construction and Transport Workers Solidarity Union should, as an industrial union, be considered party to labor-related activities carried out by industrial employers and managers. The right to unionize is protected under Article 28 of the Constitution, while any attempts to infringe on that right are prohibited by law.”

If that is the case, why did the police and prosecutors launch a simultaneous crackdown on Kan-nama? What was their purpose?

Tansa interviewed 18 union members who were arrested and detained and their family members and reviewed the court files in each case.

What has become apparent is the attempt of prosecutors and police to destroy the union through “hostage justice.”

What is hostage justice?

Hostage justice is the practice of detaining suspects for long periods of time in order to coerce confessions, exploiting the suspects’ desire to be released as soon as possible.

So how does the detention process proceed?

When the police arrest a suspect, they send him or her to the prosecutor’s office within 48 hours. The prosecutor must then decide within 24 hours whether or not the suspect needs to be detained for a further 10 days. If necessary, the prosecutor must request a judge for a 10-day detention, which the judge must authorize. If the judge approves, the detention may be extended for additional 10 days.

This will take a maximum of 23 days, after which the prosecutor will decide whether to indict the suspect and put him/her on trial.

Even after the trial begins, depending on the judge’s discretion, the person may remain in “pre-sentencing detention” until the verdict is reached.

There are three conditions for detention, as stipulated in Article 60, Paragraph 1 of the Code of Criminal Procedure.

“The accused has no fixed residence.”

“There is probable cause to suspect that the accused may conceal or destroy evidence.”

“The accused has fled or there is probable cause to suspect that the accused may flee.”

However, judges often make decisions in favor of the prosecutors, who want to extract a confession, rather than relying on the three conditions. While the prosecutors submit detailed investigative materials called a “case record,” the suspect is only asked to defend oneself during a “detention questioning” for about five minutes.

The members of Kan-nama were not at risk of destroying evidence or fleeing. They had homes. Nevertheless, they were forced to serve long periods of detention, including Chairman Yuji Yukawa’s 644 days.

Article 38, paragraph 2 of the Constitution stipulates that “Confession made after prolonged arrest or detention shall not be admitted in evidence.” Hostage justice has been criticized by the United Nations Human Rights Council and international NGOs. In recent years, Japan’s hostage justice has come to be known as “Hostage Justice,” a peculiar system that violates human rights.

However, the government and other institutions in Japan have made no attempt to change their hostage justice system.

“There are a lot of police and prosecutors involved”

Under the hostage justice system, how did the prosecutors and police pressure the detained union members? In many cases, they pressured the members to quit the union. They also pressured members’ families to convince the members to quit the union. Some examples are shown below (affiliations and titles at the time).

・Prosecutor Mayuko Yuko of Otsu District Public Prosecutor’s Office told an union member in custody, “If you continued to be a member of Kan-nama, you would be arrested and detained in the same way,” forcing him to withdraw from the union.

・Deputy Prosecutor Tada of Otsu District Public Prosecutors Office told an union member in custody that the purpose of the investigation was to destroy Kan-nama, threatening him by saying things like, “We’re going to wipe out Kan-nama,” and, “There are a lot of police and prosecutors involved.” 

・Prosecutor Kyoko Amakawa of Osaka District Public Prosecutor’s Office called the cell phone of the wife of a union member who was in custody and told her, “Your husband is doing something very bad, so you should persuade him to quit being a union member.” She frightened the wife by demanding the names of union members in Kan-nama and asking if she had been active in Kan-nama. 

・Prosecutor Hideki Tachikawa of the Kyoto District Public Prosecutors Office pressured a detained union member to quit Kan-nama, saying, “It is the chairman of Kan-nama who is at fault, and you are not at fault, so it would be better for you to quit the union.”

・During questioning, Takeshi  Izawa of Shiga Prefectural Police said, “If you had quit Kan-nama, you would have only had to undergo voluntary questioning,” “If you’re going to quit Kan-nama, we’ll find a better way,” “Is the organization more important than your children?” and, “We’ll wait patiently until you say you’re quitting the union.”

・When arresting a union member who lived alone with his middle school son, the Shiga Prefectural Police investigator threatened him, saying, “You will be away for a long time, so are you going to put your son in an orphanage?” And “We will contact your son’s middle school to let them know you have been arrested.”

・Even if gang members or former gang members are involved in the case as managers of the alleged victims of Kan-nama, the police and prosecutors will not take any action.

The views of attorney generals

What do the key officials think about the hostage justice system’s crackdown on Kan-nama?

On January 23, 2025, Tansa submitted a questionnaire to Prosecutor General Naomi Unemoto, Minister of Justice Keisuke Suzuki, National Police Agency Commissioner General Yoshinobu Kusunoki, Supreme Court Secretary General Atsushi Ujimoto, and Prime Minister Shigeru Ishiba .

After citing the specific examples above and asking them to point out any factual errors if there is any, we asked the following questions:

“Doesn’t this go against Article 28 of the Constitution, which guarantees the rights of labor unions?”

“Doesn’t this violate international treaties that prohibit arbitrary arrest and detention?”

“Why were gang affiliations and former gang members not questioned for their involvement in the incident?”

In response to the deadline of February 3, the Public Relations Office of the Minister’s Secretariat of the Ministry of Justice sent the following response via email at 4:34 p.m. on January 28.

As this is a matter relating to an individual case, we will refrain from answering.

At 5:12 p.m., approximately 30 minutes after the Ministry of Justice’s response, the Planning Section of the Research and Coordination Division of the Supreme Public Prosecutors’ Office sent the following response by email as “Response from the Supreme Public Prosecutors’ Office.”

As this is a matter relating to an individual case, we will refrain from answering.

At 1:33 p.m. on January 29, the Supreme Court Press Division’s Nakamura called Tansa’s editor-in-chief Watanabe’s mobile phone number, which Tansa had listed as the contact information for the questionnaire.

“We have no response to the questionnaire dated January 23.”

We had requested a written response, so when we asked them to respond in writing again, he said, “We usually respond to interviews by phone.” When we asked him again to respond in writing because we wanted to have a proper record, he said, “We will consider it.” We haven’t heard from them since.

Even though the deadline had passed, there had been no response from the National Police Agency or the Cabinet Secretariat. We will report on the matter once we receive a response.

Profiles of those responsible for “hostage justice”

Prosecutor General Naomi Unemoto, Minister of Justice Keisuke Suzuki, Commissioner General of the National Police Agency Yoshinobu Kusunoki, Secretary General of the Supreme Court Atsushi Ujimoto, and Prime Minister Shigeru Ishiba all bear a great deal of responsibility for this situation. Below is a brief profile of each of them and some quotes that give a glimpse into their views on the judiciary.

Naomi Unemoto, Prosecutor General

She was appointed as a prosecutor in 1988. After serving as the Kochi District Public Prosecutors Office, Director of the Ministry of Justice’s Rehabilitation Bureau, and Superintendent of the Tokyo High Public Prosecutors Office, she became the first female Prosecutor General in July 2024. On the Public Prosecutor’s Office website, she states, “Bearing in mind that the public prosecutor’s offices is founded on public trust, I would like to do my best to ensure that all officials of public prosecutor’s offices across the country are deeply aware of their responsibilities and carry out their duties with enthusiasm.”

When Iwao Hakamada, a victim of hostage justice, was acquitted in his retrial, she made the following statement in announcing her intention not to appeal:

“The reasons behind this ruling contain many problems and are completely unacceptable, so we believe that we should appeal it and seek the judgment of a higher court. However, we also took into account the fact that Mr. Hakamada has been in an unstable legal position for an extended period of time due to the inconsistent judicial decisions made during the retrial hearings. Thus, after careful consideration, we have concluded that it is not appropriate for the prosecution to appeal this ruling and allow this situation to continue.”

“As a result, Mr. Hakamada’s legal status has been left unstable for a considerable period of time. As the prosecutors’ office, which plays a part in the criminal justice system, we feel sorry about this. The Supreme Public Prosecutors’ Office would like to conduct the necessary investigation into why the retrial request procedure in this case has taken so long.”

Keisuke Suzuki, Minister of Justice 

He served in the Ministry of Finance and the Ministry of Health, Labor and Welfare, and has been a member of the House of Representatives since 2005. He served as Deputy Secretary-General and Chairman of the Financial and Monetary Affairs Committee of the Liberal Democratic Party. He joined the Cabinet for the first time in November 2024 as Minister of Justice in the Ishiba Cabinet. At a press conference after his first day at work, when asked about the nature of prosecutors’ interrogations, he answered as follows:

“The prosecutor’s investigations and trials must be handled properly. I believe this goes without saying. The prosecutor’s office’s activities are indeed based on public trust, so I believe we must never allow anything to cast doubt on the appropriateness of prosecutorial power. This is the foundation of the prosecutor’s activities, and I would like to firmly emphasize this point.”

“Whether or not the activities of individual prosecutors are being carried out appropriately is of course something that the prosecutors’ authorities must take the lead in determining, but at the same time, as the Minister of Justice, I also believe that it is necessary for me to closely monitor this, and I intend to take firm action in this regard.”

Yoshinobu Kusunoki, Commissioner General of the National Police Agency 

He assumed the position of Commissioner General of the National Police Agency on January 27, 2025. He served as the head of the Criminal Affairs Division of the Chiba Prefectural Police, the Director General of the National Police Agency’s Traffic Bureau, and as a secretary to Yoshihide Suga when he was Chief Cabinet Secretary. At his inauguration press conference, he emphasized his achievements in reducing the number of fatalities from accidents, drawing on his extensive experience in the traffic sector. He spoke about measures against anonymous and fluid crime groups and cybercrime, and security at the Osaka Expo, but did not mention correcting the investigations that violate the Constitution. Reporters from member companies of the press club attended the press conference, but no questions were asked about correcting the investigations.

Following his appointment as Minister, the Mainichi Shimbun of February 1 commented on Kusunoki’s personality and praised him highly.

“He claims that his greatest strength is tenacity. When faced with a task that seems to be progressing slowly, he tells his colleagues, ‘It only takes one second to give up. Let’s try a little harder.’ He also makes an effort to create a positive environment, and those around him admire him as ‘kind yet tough and reliable.’”

Atsushi Ujimoto, Secretary General of the Supreme Court

The Supreme Court’s Secretariat is responsible for judicial administration, including personnel and budget matters within the court. He also answers questions in the Diet. He became Secretary-General of the Supreme Court after serving as Chief Judge of the Tokyo District Court, Chief Accounting Bureau of the Supreme Court, and Chief Judge of the Kofu District and Family Courts. According to the Sankei Shimbun dated September 11, 2024, Ujimoto said the following at his inauguration press conference:

“It is necessary to think calmly and take on bold challenges at times. I would like to fully grasp the needs for justice and do my utmost to improve the environment.”

Shigeru Ishiba, Prime Minister

Regarding the confirmation of Iwao Hakamada’s innocence, he said this at a party leaders’ debate held at the Japan National Press Club in October 2024.

“Of course the government must feel a certain degree of responsibility for putting Mr. Hakamada, who is elderly, in such a situation.'”

“I would like to reach a conclusion through further discussion as to whether the retrial should be conducted in a more rational manner so that the rights of the defendant are not violated. At the same time, the authorities in charge of the prosecution will also carefully examine whether the investigation is being conducted appropriately.”

Hostage Justice: All articles