"Yakuza with the Cherry Blossom Badge"—Two officers from the Osaka Prefectural Police's Fourth Investigative Division arrested on suspicion of assault during a house search. Former officers voice concerns, saying "It's unacceptable in this day and age," shaking the pride of the "aggressive Fourth Division."

1. What Happened: Arrests in the "Aggressive Fourth Division"

On August 3, 2025, the Osaka Prefectural Police arrested Assistant Inspector Chikara Tokinaga (51) and Sergeant Yusuke Sakaguchi (32) of the Fourth Investigation Division on suspicion of special public official assault and abuse. The charges allege that on the night of July 15, they assaulted a man in his 20s during a house search, including slapping his face and hitting his abdomen multiple times. Tokinaga, who was the on-site supervisor, denies the charges, while Sakaguchi admits to them. It is reported that more than 20 investigators were present at the scene, and the prefectural police are investigating the involvement of others.Asahi Shimbun

The incident occurred during an investigation into suspected violations of the Employment Security Act against "Natural," a scout group considered one of the largest in the country. It happened during a house search of a rental office in Nishi Ward, Osaka City, believed to be the group's base. The search took place between around 9:15 PM and 9:35 PM.Asahi Shimbun

The men from the group, who were arrested after the investigation, reported to their lawyers that they were assaulted by police officers. The prefectural police released them on August 1 and reportedly decided to return the seized materials, considering them likely to be illegally collected evidence.video.yahoo.co.jp

2. What Happened at the Scene: Smartphone Passcodes and Reports of "Being Beaten by 3-5 People"

According to multiple reports, investigators at the scene attempted to verify the passcodes of smartphones found in the room, but the men refused. This reportedly triggered the assault. The men claimed they were "beaten by 3-5 investigators" and "stepped on and slapped while in a defenseless state," with bruises confirmed on their faces and bodies.Kansai Television KanteleAsahi Shimbun

This "battle over passcodes" is a frequent issue in recent search and seizure scenes. The permissibility of forcing device unlocks as a compulsory measure involves complex issues such as the scope of warrants, forced confessions, the right to remain silent, and practical operations. The prefectural police's move to return seized items suggests that doubts about the legality of the procedures arose to the extent that the exclusion of illegally collected evidence is anticipated. Practically, the method of acquisition during searches can shake the entire subsequent proof, making it a typical example.video.yahoo.co.jp

3. "Yakuza with the Cherry Blossom Crest": The Historical Context of the "Aggressive Fourth Division"

The Fourth Investigation Division was newly established in 1961 and became known for its "aggressive investigations" in cases involving gangs like the Yamaguchi-gumi. Historical footage of raids on gang offices captures strong commands and shouts. A former gang leader described Osaka as having an image of "burning in," likening the police to "yakuza with the cherry blossom crest (police badge)." A former anti-gang detective testified that there is an underlying psychology of "not being underestimated."Kansai Television Kantele

This "tough tradition" had a certain rationality in the context of an era when gangs did not hesitate to use force. However, with the enforcement of the Anti-Organized Crime Law and the diversification of criminal organizations (such as "half-gray" groups and anonymous, fluid "Tokuryu"), the traditional "push-through" style is increasingly clashing with modern standards that demand evidence management, human rights considerations, and visibility and recording.Kansai Television Kantele

4. Voices from Inside and Outside: "Provoked" and "Not Professional"

A former anti-gang detective from another prefecture suggested that the officers "might have been provoked" or "set up." An Osaka Prefectural Police OB commented, "In the past, we might have punched walls during raids, but that's not acceptable now. We must not forget the premise of recording." While some with experience in the Fourth Division say, "There is no culture of using violence; it's purely an individual issue," others offer a harsh assessment, stating, "This time, it was not professional as an investigation."Kansai Television Kantele

Furthermore, there are concerns about the impact on the investigation into "Natural," which was the starting point of the incident. A Fourth Division insider remarked, "It happened during an investigation into a group that exploits women, and with the release, the 'investigation is almost busted.'" This succinctly illustrates the significant loss from the frontline perspective.Kansai Television Kantele

5. What is "Natural": The True Target

"Natural" is a large-scale scout group originating from the Kanto region, known to have a top-down communication network utilizing social media. It is suspected of illegal activities related to the mediation of women, and arrests of members have been reported in various locations, highlighting its "militant" aspect. Its expansion into Osaka has been confirmed, and the National Police Agency had instructed to strengthen crackdowns on it as an "anonymous, fluid crime group" (Tokuryu).Asahi Broadcasting Television

For the Fourth Division, this blunder was therefore a painful one. As its sphere of influence expands in Osaka, the procedural violation suspicion in an investigation that was a matter of prestige could lead to losing the overall strategic advantage.Asahi Broadcasting Television

6. Legal Basics: Special Public Official Assault and Abuse and the Consequences of Illegally Collected Evidence

When police officers commit assaults or other acts against suspects or defendants in the course of their duties, they may be charged with the crime of special public official assault and abuse. In this case, the prefectural police proceeded with arrests, and the head of the inspection office commented, "It is truly regrettable." The seized materials are considered likely to be illegally collected, and the decision to return them reflects the practical operation of excluding evidence obtained through illegal procedures. If the legitimacy of the evidence collapses, the handling of related "fruits of the poisonous tree" will also be strictly scrutinized, and the path to prosecution itself becomes narrower.video.yahoo.co.jpAsahi Shimbun

7. Bottlenecks in Field Operations: Smartphones and Passcodes

Digital evidence is the "heart" of a case, but the legal procedures surrounding passcodes are delicate.

• Voluntariness of Acquisition: Forcing unlocks against a suspect's will raises doubts about forced confessions and the violation of the right to remain silent.

• Specificity of Warrants: If the seizure targets and methods are not clearly defined, the risk of illegal collection increases significantly later.

• Division of Labor in Practice: If coordination between the field, analysis, and prosecution is unclear, "crossing the line" can easily occur through field judgment.

The sequence of events leading from passcode refusal to assault in this case symbolizes the side effects of "crossing the line."Kansai Television Kantele

8. Updating to "Observed Investigations": Specific Measures for Preventing Recurrence

(1) Ensuring Continuous Recording
The scope of using body cameras and fixed cameras during search and seizure should be more specifically defined in prefectural police regulations, including "the permissibility of stopping recordings and log preservation," "the operation of third-party presence," and "the verifiability of footage."

(2) Standardizing Passcode Operations

• A checklist specifying the necessity, method, and phase (field/office) of device unlocking

• Consent form templates for voluntary disclosure and procedures for stopping when consent is withdrawn

• A risk decision table including the permissibility of using biometrics
  
  
  

(3) Communication Training
Standardize training with role-playing for de-escalation techniques in provocative situations, establishing a skill set separate from the Fourth Division's "intimidation" tradition.

(4) Dual Supervision
Appoint a "procedural supervisor" separate from the on-site supervisor, granting them the authority to stop "crossing the line" before it happens.

(5) Prompt Monitoring
Routine the provisional restriction of duties and prompt retrieval of footage once a lawyer's report or medical opinion is received.

9. How to Inherit the Fourth Division's On-Site Sensibility: Redefining "Strength"

The on-site psychology of "not being underestimated" by gangs and half-gray groups comes from an instinct for ensuring operational safety and strategic advantage. However, the legitimacy of procedures is the strength itself. If doubts about illegal procedures arise, the investigation collapses, and the organization's credibility is damaged.
The self-reference of former Fourth Division members as "not professional" is nothing less than a message to update the Fourth Division's DNA from "violence" to meticulousness and courage.Kansai Television Kantele

10. Reviewing the Timeline

• July 15, around 21:15-21:35: House search at a rental office in Nishi Ward, Osaka City (targeting "Natural"). Over 20