What happened at the scene of the seizure by parties involved?\u2015\u2015The structural problem of organizational decision-making that ordered the door to be opened without considering the leakage situation, directed at a person of interest whose personal information continued to be exposed in the Mamizuka memo<\/p>\n\n\n\n
Global Union (National Tax Union) | Tokyo Metropolitan Area Youth Union Federation
April 22, 2026 | Official Statement<\/p>\n\n\n\n
This statement expresses the official view of our association regarding the serious procedural contradictions at the scene of the seizure against related parties conducted by the 21st Inspection Division of the Tokyo Regional Taxation Bureau in October 2025, as well as their connection to the information leak incident that served as the background.<\/p>\n\n\n\n
Hideto Nakamura, chief investigator of the 21st Inspection Division at the Tokyo Regional Taxation Bureau, restrained the provision of information from our union member in this case and made statements to the effect of \"Do not give instructions.\"<\/p>\n\n\n\n
What is important here is the fact that our union member who provided the said information was neither a suspect nor a person of interest, but an ordinary taxpayer. In other words, our union member was not in a position of being suspected in this inspection investigation, nor positioned as a person of interest subject to a collateral investigation; they merely provided information to the National Tax Agency as a private citizen who was a pure third party.<\/p>\n\n\n\n
Here, an extremely serious logical contradiction arises.<\/p>\n\n\n\n
The National Tax Agency and national tax bureaus have established \"information provision regarding untaxed or uncollected taxes\" portals on their respective websites, widely inviting information from the general public. This is an official channel to systematically incorporate public cooperation in order to ensure the effectiveness of tax administration.<\/p>\n\n\n\n
The National Tax Agency, with one hand, calls on the general public to provide information, while with the other hand, it restrains a taxpayer who actually provided information by telling them, \"Do not give instructions.\" This structure means that the On-Site Investigation Department on the ground undermined the purpose of the information-providing channel that the National Tax Agency itself established as a system.<\/p>\n\n\n\n
Moreover, the provider of said information was an ordinary taxpayer, neither a suspect nor a person of interest. To evaluate voluntary information provided by an ordinary taxpayer as an \"instruction\" and deter it,<\/p>\n\n\n\n
First, it directly contradicts the purpose of the information provision system promoted as a policy by the National Tax Agency,<\/p>\n\n\n\n
Secondly, it arbitrarily restricts the provision of information\u2014which is an expression of the citizens' freedom of expression (Article 21 of the Constitution)\u2014for administrative convenience,<\/p>\n\n\n\n
Thirdly, and above all, it means that the Inspection Department closed the cooperation window that the National Tax Agency itself urged the public to use in its on-site operations.<\/p>\n\n\n\n
However, precisely at the seizure site of that very same inspection investigation, an order to the effect of \"open the door\" was issued by the Tokyo Regional Taxation Bureau to the witness who was the target of the seizure.<\/p>\n\n\n\n
Moreover, as will be discussed later, the said witness is a party who has continued to have their personal information exposed over a long period through the Mamizuka memo.<\/p>\n\n\n\n
Here, a logical contradiction arises twice over.<\/p>\n\n\n\n
On the one hand, they evaluated the voluntary provision of information from a mere taxpayer as an \"instruction\" to stop it, attempting to control that taxpayer's expression; while on the other hand, they tried to override with an administrative order the most fundamental expression of free will\u2014namely, keeping the door closed by the witness herself, whose personal information continued to be exposed through leaks\u2014by demanding that she \"open the door.\"<\/p>\n\n\n\n
In other words, this practice exposes a structure that conveniently applies a double standard to the autonomy of citizens: it refuses to accept information provided by an individual taxpayer, yet demands that witnesses comply with orders from the Tokyo Regional Taxation Bureau. We are forced to conclude that this directly contradicts the fundamental principles of voluntary tax audits.<\/p>\n\n\n\n
The National Tax Agency has established a system to broadly accept information from the general public through tools such as the \"Submission of Information on Tax Evasion and Tax Arrears\" form on its website. This embodies the fundamental principle of modern administrative management, which is to ensure the transparency and effectiveness of tax administration through the cooperation of the citizenry.<\/p>\n\n\n\n
What should be made clear here is the basic structure in which the citizens providing information are not limited to those summoned by the National Tax Agency as suspects or persons of interest. Rather, information provided by ordinary citizens who are neither suspects nor persons of interest is the core target of this system.<\/p>\n\n\n\n
Nevertheless, in this case, the 21st Inspection Division of the Tokyo Regional Taxation Bureau's Inspection Department characterized information provided by our union member\u2014who was neither a suspect nor a person of interest\u2014as an \"instruction\" and obstructed it. This is<\/p>\n\n\n\n
First, it contradicts the purpose of the information provision system currently promoted on the National Tax Agency website,<\/p>\n\n\n\n
Second, it contradicts the motives of citizens who provide information\u2014their public-spiritedness, such as wanting to \"cooperate in achieving correct tax administration\" or \"provide information if it helps establish facts\"\u2014in practical field operations;<\/p>\n\n\n\n
Third, as a result, it undermines the very credibility of the reporting system officially promoted by the National Tax Agency.<\/p>\n\n\n\n
Assuming there were unnecessary parts in the content of the information provided from the administrative perspective, that judgment should suffice to be made in the evaluation after receipt. Restraining the provider at the stage of information provision by saying \"do not instruct\" is nothing other than abandoning the inherent official responsibility of the administration to scrutinize and select information, and constitutes a practice of closing the door at the initial stage of public cooperation.<\/p>\n\n\n\n
The questioning and inspection powers stipulated in Article 74-2 and subsequent articles of the Act on General Rules for National Taxes are designed as voluntary investigations that do not involve compulsory responses from the subject, and the Supreme Court ruling (Grand Bench Judgment of July 10, 1973, Kawasaki Minsho Incident) clearly states that even if a tax investigation has the preliminary character of criminal proceedings, compulsory measures without a warrant are not permitted.<\/p>\n\n\n\n
Witnesses who are contacted during the scene of a seizure\u2014that is, third parties who happen to be present at the scene not as suspects themselves, but as persons related to them\u2014are, in the first place, not even in a position of being suspected, but are purely third parties.<\/p>\n\n\n\n
The witness's choice not to respond while keeping the door closed<\/p>\n\n\n\n
First, it is an extremely common-sense act of self-defense to verify the identity and purpose of someone who has made a sudden visit,<\/p>\n\n\n\n
Secondly, since it is a voluntary response in situations without a warrant, the freedom to decide whether or not to respond is a legally protected act,<\/p>\n\n\n\n
Thirdly, it is also an expression of rational self-defense in light of the information leakage risks described below.<\/p>\n\n\n\n
Fourth: The Information Leak Incident Known as the Mamizuka Memo \u2014 The Witness in Question Was \"a Party Whose Personal Information Had Been Exposed for a Long Period of Time\"<\/p>\n\n\n\n
Now, as an extremely important special circumstance in this case, is the fact that the witness in question was a party who had continued to have their personal information exposed over a long period through the Mamizuka memo.<\/p>\n\n\n\n
As of February 2025, the Mamizuka Memo is internal information that was shared and documented with tax accountant Takeji Mamizuka (a former National Tax Agency investigator) during face-to-face investigations involving Chief Inspector Tsuyoshi Shimazaki (Kumamoto Regional Taxation Bureau, Investigation and Intelligence Department, Investigation Division 3), Senior Inspector Nobuhiro Kawaguchi, Inspector Keisuke Ota, and others. It has been confirmed as an objective sequence of events in this case that the memo was subsequently distributed to an extremely wide range of third parties.<\/p>\n\n\n\n
This memo contained detailed information, including the names, roles, and business relationships of multiple parties concerned\u2014including the relevant witness\u2014as well as the policy for establishing suspicions. In other words, due to the dissemination of information originating from the National Tax Agency, the relevant witness had been placed in a state where their name and involvement were exposed to outsiders for an extended period.<\/p>\n\n\n\n
The actual harm caused by this flow of information is not abstract. Specifically,<\/p>\n\n\n\n
The fact that the risk of someone posing as an individual suddenly visiting had continuously arisen over a long period of time as a result of the said witness's name and their \"relationship with the investigation target\" being communicated together to the outside<\/p>\n\n\n\n
The situation was such that the witness herself could not completely rule out the possibility that a visit claiming to be from the National Tax Agency was actually an impersonation by a third party who had obtained her name through a data breach.<\/p>\n\n\n\n
An illegal demand incident involving 4 million yen occurred for those involved, according to someone who actually knows Director-General Go Shimasaki, Chief Investigator Nobuhiro Kawaguchi, and Tax Accountant Takeji Mamitsuka, and that fact had also been reported to the Kumamoto Regional Taxation Bureau.<\/p>\n\n\n\n
The situation where a risk similar to the incident at the Osaka Regional Taxation Bureau, where taxpayer information for 259 cases was externally transmitted under the instruction of an individual posing as a police officer (announced in April 2026), could also extend to the person of interest in this case.<\/p>\n\n\n\n
These are the circumstances that objectively substantiate the rationality of the witness's action in demanding confirmation of identity and purpose while keeping the door closed.<\/p>\n\n\n\n
Article 36, Paragraph 1 of the Penal Code stipulates that self-defense is \"an act unavoidably performed to defend the rights of oneself or others against imminent and unlawful infringement\" and shall not be punished. However, passive acts of self-defense such as closing a door to verify a visitor's legitimacy, as in this case, do not constitute punishable aggressive acts in the first place, and fall well within the scope of lawful acts prior to examining the requirements for self-defense.<\/p>\n\n\n\n
To make a more accurate legal assessment, the response of the witness in this case is<\/p>\n\n\n\n
First, as a holder of the right of residence under Article 130 of the Penal Code, this is an exercise of the constitutional right to personal autonomy to decide whom to permit to enter the premises of one's home,<\/p>\n\n\n\n
Secondly, as a fulfillment of the duty to exercise reasonable care to verify the authenticity of visitors under circumstances where one's name has been circulating externally for a long period due to a data leak,<\/p>\n\n\n\n
Third, as passive self-defense within the limits of self-help under civil law, it is an act that carries no illegality whatsoever.<\/p>\n\n\n\n
Nevertheless, the fact that the Tokyo Regional Taxation Bureau demanded the doors be opened in a commanding tone forces us to conclude that they overstepped the boundaries of voluntary investigations without a warrant in their on-site operations.<\/p>\n\n\n\n
What cannot be overlooked in this matter is<\/p>\n\n\n\n
First, the information leak known as the Mamitsuka memo was caused by the same organization\u2014the tax office (the Kumamoto Regional Taxation Bureau and the National Tax Agency's supervisory line)\u2014and<\/p>\n\n\n\n
Secondly, under the influence of that information leak, despite the witness bearing the risk that \"their name had been circulating externally for a long period of time,\"<\/p>\n\n\n\n
Third, the Tokyo Regional Taxation Bureau, without considering the leakage situation, suddenly visited the relevant witness and demanded in a commanding tone that the door be opened.<\/p>\n\n\n\n
This is the structure.<\/p>\n\n\n\n
That is to say, given the fact that their own organization had caused a data leak, the rationality of the witness closing the door should naturally have been predictable prior to the visit. Despite this, the fact that they resorted to a commanding response without any consideration for the leak means that the witness's duty of care for safety was subordinated to the administrative side's operational convenience.<\/p>\n\n\n\n
And on the other hand, while reacting like this, well-intentioned tips from a taxpayer who is neither a suspect nor a person of interest are dismissed as \"instructions\" and halted. This double standard externally exposes the distortion of priorities in the National Tax Agency's operational practices: closing the doors when public cooperation is needed, while overstepping the bounds of authority when making coercive contact.<\/p>\n\n\n\n
Based on the above, our union requests that Lead Inspector Hideto Nakamura and Inspector Toru Nakajima of the 21st Inspection Division, Investigation Department, Tokyo Regional Taxation Bureau, provide a formal written response to the following matters.<\/p>\n\n\n\n
First, the organizational view on the legal basis for evaluating information provided by a taxpayer who is neither a suspect nor a person of interest as an \"instruction\" and stopping it, as well as the consistency with the information provision system officially promoted by the National Tax Agency.<\/p>\n\n\n\n
Secondly, to what extent did you recognize prior to the visit that, due to the information leak incident known as the Mamizuka Memo, the said witness's name had been circulating externally for a long period? If you did recognize this, why did you not adopt a visit protocol that anticipated defensive actions by the witness (such as advance contact, a process for presenting identification, prior coordination through a legal representative, etc.)?<\/p>\n\n\n\n
Thirdly, while leaving the information leak caused by the Mamizuka memo unaddressed for a long period, upon which provisions from Article 74-2 onward of the General Act on National Taxes was the legal basis for demanding that the person of interest open the door in a commanding tone based?<\/p>\n\n\n\n
Fourth, when comparing the information leak incident at the Osaka Regional Taxation Bureau (disclosed in April 2026) and the Mamizuka memo leak incident in this case, what operational differences are established from the perspective of witness protection?<\/p>\n\n\n\n
Fifth, is it possible for the organization to provide a consistent explanation regarding the double standard applied in this case, where the practice of \"stopping information provision from a taxpayer\" and the practice of \"ordering a witness to open the door\" were invoked simultaneously?<\/p>\n\n\n\n
Conclusion: Public cooperation is the lifeline of tax administration<\/p>\n\n\n\n
The National Tax Agency is calling on the general public to provide information through its website. This initiative is based on the fundamental understanding that tax administration cannot function without the cooperation of the public.<\/p>\n\n\n\n
Nevertheless, one taxpayer who actually provided information is ordered to stop with \"do not instruct,\" while at the same time, a reference person whose personal information has been continuously exposed for a long time due to a data leak is ordered to keep the door open. If this double standard is left unchecked, the very whistleblowing system promoted by the National Tax Agency will lose the public's trust.<\/p>\n\n\n\n
With this statement, our union strongly urges the Tokyo Regional Taxation Bureau and the supervisory line of the National Tax Agency to fundamentally review operational practices on the ground and take organizational measures to restore trust in the whistleblower system.<\/p>\n\n\n\n