HR Internal Investigations 2026

Last Updated February 04, 2026

Japan

Law and Practice

Authors



AI-EI Law Firm was established in 2019, mainly by lawyers from Nishimura & Asahi, and specialises in corporate dispute resolution and labour/employment matters. The name “AI-EI” is derived from the Japanese word “相栄” (pronounced “I-A”), which means collective prosperity. To achieve collective prosperity with its clients, the firm takes the unrivalled approach of not only accurately analysing and categorising a large amount of past data (in this case, vast experience and knowledge), like AI does, but also using elements of EI (emotional intelligence) so that clients’ true needs are properly understood. Thus, clients are guaranteed practical solutions that address the substance of the dispute – not only from the perspectives of “economic rationality” and “efficiency” required in business, but also with the humanity and sensitivity required when dealing with people who are the subjects and the objects of disputes and labour issues.

In Japan, an employer typically initiates an HR internal investigation when it receives a whistle-blowing report or consultation from employees regarding an HR issue (eg, harassment). Investigations are also triggered when the regulatory authority starts an inspection or a third party brings a lawsuit against the employer.

Usually, the employer carries out an HR internal investigation based on the employment contract and the Work Rules, which require employees to comply with the employer’s instructions and orders. Furthermore, in its judgment of 13 December 1977 (Minshu Vol 31, No 7, p1037, Employee v Fuji Heavy Industries Ltd), the Supreme Court ruled that an employer can carry out a fact-finding investigation in the event of a violation of a company’s order – regardless of the existence of the Work Rules’ description – so that it can clarify the content and nature of the violating conduct (as well as the rules it is in violation of) and issue the instructions required to restore the company’s order, or implement sanctions against the violator. In addition, company directors owe a duty of care, which includes carrying out necessary fact-finding on important issues.

An employer with more than 300 employees is required to establish a whistle-blowing channel through which employees may report violations of laws and their concerns (Article 11, paragraph 1 of Act No 122 of 2004 – the “Whistle-Blower Protection Act”). A person monitoring such whistle-blowing channel should treat the report and its information anonymously if the whistle-blower’s report was submitted anonymously (Article 11, paragraph 2 of the Whistle-Blower Protection Act and its guidelines).

There are no specific rules in Japan regarding who is responsible for carrying out an HR internal investigation. In the case of organisational misconduct or a huge violation, the board of directors usually appoints outside counsel or an outside investigation committee to carry out an objective investigation. Conversely, in the case of a relatively small matter, the HR department or its counsel may carry out an HR internal investigation.

If the investigation involves a legal or accounting matter, a professional expert (eg, a licensed lawyer and/or accountant) may be involved at an early stage. If the investigation is triggered by a whistle-blower’s report, the investigator handling such information must be designated by the company based on the Whistle-Blower Protection Act, and they cannot share information about the whistle-blower outside the team.

According to the relevant Japanese laws, an employer is responsible for taking preventative measures against harassment, including sexual harassment, maternity harassment and power harassment; moreover, the employer should carry out an HR internal investigation if an act is perceived as harassment. In addition, if an employer perceives a risk of violation of the law, based on a whistle-blower’s report, the employer should carry out an HR internal investigation and take corrective and preventative measures as well. If the employer does not carry out any investigation and/or take any preventative measures, it will be in violation of its duty of care towards its employees under Article 5 of Act No 128 of 2007 (the “Labour Contracts Act”) and/or in violation of the related directors’ duty of care.

There are situations in which an HR internal investigation is not appropriate, and in such cases the employer may take alternative measures instead. By way of example, if an HR department is suspected of committing organisational misconduct or an HR employee/officer may have committed harassment internally, it would be more appropriate for the board of directors or an auditor to carry out an investigation instead of an HR internal investigation taking place.

An employer has the discretion to decide whether and when to carry out an HR internal investigation, based on the content and severity of the risk it perceives. This decision is usually a matter of business judgement. However, if the risk relates to a violation of the law, an employer must carry out an investigation promptly.

Generally, the reporter and the respondent do not have the right to be informed of whether an HR internal investigation will be initiated. It is standard practice not to notify the respondent, as it is often considered inappropriate to allow the respondent to infer that a report has been filed.

There are no specific requirements regarding the notice period and the information to be provided to the reporter. With respect to the respondent, when disciplinary action is anticipated, it is procedurally desirable to give the respondent an opportunity to present an explanation and disclose the reason of expected disciplinary action. Such procedures are often stipulated in the company’s Work Rules. However, it is advisable not to disclose the existence and the details of the report, as it creates the potential for retaliation.

On the other hand, when an employer receives a whistle-blowing report, it is recommended that the employer informs the whistle-blower of whether an internal investigation will be initiated. If 20 days have passed since the date of the whistle-blowing report and no notice of an investigation has been provided or an investigation is not initiated without a legitimate reason, the whistle-blower will be able to make a whistle-blowing report to third parties, such as mass media (Article 3, Item 3 of the Whistle-Blower Protection Act).

Under the government guidelines, it is considered desirable to report both the commencement and the progress of the investigation. After the end of the investigation, an employer will report the result of the investigation, and the report should be simple and succinct. In contrast, with respect to the respondent, in cases where merely communicating the existence of a whistle-blowing report would lead to the identification of the whistle-blower, such notification must not be disclosed to the third party without just cause (Article 12 of the Whistle-Blower Protection Act). Moreover, disclosing information to the respondent may constitute a violation of the law.

In the event of leakage of certain types of personal information, the employer must report to the Personal Information Protection Commission in accordance with Act No 57 of 2003 (the “Act on the Protection of Personal Information”). In addition, a government official must report to the authorities if they suspect that a crime has been committed (Article 239, paragraph 2 of Act No 131 of 1948 – the “Code of Criminal Procedure”).

In general, however, there are no situations in which the initiation of an HR internal investigation must be reported to the authorities. Nevertheless, there are some cases in which the employer may decide to report the matter to the authorities (eg, the regulatory authorities, the police and the public prosecutor’s office), when such report will be advantageous to the employer’s position and beneficial to the case.

Typically, an employer does not require the relevant party to sign confidentiality agreements and/or non-disclosure agreements (NDAs) for an HR internal investigation. However, it is common practice for the employer to stipulate a confidentiality clause in an employment contract and in the Work Rules.

The employer must also instruct the relevant party not to disclose any information related to the investigation, with the warning that a breach of confidentiality will result in a breach of contract and be subject to disciplinary action. For investigations in cases of whistle-blowing, it is common practice for the employer to require the investigator to sign an NDA at the time of appointment.

In Japan, it is possible to conduct a preliminary investigation before a full HR internal investigation. However, there is no clear distinction between a preliminary investigation and a full HR internal investigation. Therefore, it is common practice for the investigator to begin the preliminary fact-finding process at an early stage and then expand the scope of the investigation based on the results of the fact-finding process.

The type and number of interviewees will depend on the nature and factual basis of the case. Typically, an employer will interview a reporter, a victim, a witness and a perpetrator.

An employer may request or order employees to participate in the interview and to sincerely co-operate with the investigation, based on the employment contract or the Work Rules. However, an employer should be sensitive to the feelings and mental health of the interviewees, especially with regard to the victim.

The interview can be conducted remotely or face-to-face. However, given the possibility of interviewees refusing to answer questions in an online environment, the risk of secret recordings and the advantage of being able to observe the interviewee’s attitude and behaviour more effectively, face-to-face interviews are preferable, especially when interviewing important individuals.

In Japan, there are no specific rules regarding the number of interviewers in HR internal investigations.

However, regarding the recommendation of resignation, the Supreme Court has ruled that repeated interviews after a clear rejection by several interviewers are considered an act of tort against the employee (Supreme Court judgment of 10 July 1980, Employee v Shimonoseki City, Shu-Min No 130, p131.). In view of this ruling, it is advisable for there to be two or three interviewers; one will be the chief interviewer and the rest will take minutes. In the case of hostile interviewees in particular, to avoid disputes over the appropriateness of the methods of investigation or allegations of harassment (and also to prevent disagreements over what was said), interviews will not be conducted by a single person, so as to maintain numerical superiority.

When selecting interviewers, the employer should consider factors such as the nature of the case and the gender and objectivity of the interviewers, as well as the age difference between interviewers and the interviewee, in order to ensure a smooth interview process.

Normally, there are no instances in which a neutral third party should be present during an interview. If a third party is present and comments on the questions and/or answers, the results of the interview and the interviewee’s memory may be distorted or severely impaired; therefore, it is recommended that third parties do not observe the interview.

If the victim requests the attendance of a support person, and such attendance is deemed unavoidable, the employer should consider accepting such request. However, support persons should typically not be permitted to attend the interview, and the employer maintains the discretion to deny their presence. If a support person accompanies the victim at the interview and comments on the questions and/or answers, there is a risk that the results of the interview and the interviewee’s memory may be distorted or severely impaired (as described in 3.5 Neutral Party). Furthermore, it will be difficult to impose the duty of confidentiality on the support person, if such a person attends and know the confidential information.

The same principle applies to lawyers. Although the interviewee can request the presence of their lawyers, they do not have the right to be accompanied by their lawyers, and the company may refuse the presence of a lawyer based on its managerial authority over the workplace and its authority to conduct the investigation. However, in practice, refusing a lawyer’s attendance could adversely affect negotiations. Therefore, companies may consider allowing the lawyer to attend, provided that the lawyer is clearly instructed not to interfere with the conduct of the interview.

Unlike the supporter, who is usually a lay person, the lawyer owes a duty of confidentiality under the Attorneys Act and other regulations (Article 23 of the Attorneys Act). However, when an employer allows the lawyer to attend, it is advisable to warn the lawyer that a breach of such a duty may result in his/her misconduct and professional risk.

There is no specific information that the interviewers must provide to interviewees at the beginning and/or end of the interview, nor is there a Miranda-like warning. However, an interviewer will typically explain that:

  • intentionally lying and/or concealing the facts and evidence will result in sanctions, including disciplinary action; and
  • disclosure of the information outside the interview is prohibited.

In addition, if the lawyer assumes the role of interviewer, it is common to clarify that they are conducting the interview either in a third-party capacity or as a legal representative of the company. If the lawyer participates in an investigation in a neutral and third-party capacity, and declares such status to the interviewee, the lawyer should not be involved in the company’s actions against the interviewees (including disciplinary action and claims).

It is advisable for an interviewer to agree to stop the interview, taking into account the interviewee’s health condition. If the interviewer refuses to stop the interview, they may face allegations of unlawful arrest, imprisonment or harassment.

However, it would be better to keep accurate and detailed minutes of the interview. If the interviewee suddenly changes their attitude and requests that the interviewer stop the interview after being asked an unfavourable question, the minutes can be used as evidence of what happened at the interview.

An interviewer should take minutes, and summarised minutes are allowed. Although the interviewer typically does not allow the interviewee to review the minutes, there are cases in which the interviewer strategically requests the interviewee to review the minutes and sign them.

It is at the interviewee’s discretion whether they sign the minutes. However, once they sign the minutes, the evidentiary value in court is strengthened and the contents of such minutes are considered to be based on the interviewee’s actual intention (Article 228, paragraph 4 of Act No 109 of 1996 – the “Code of Civil Procedure”). The interviewer or an internal employee may take minutes, but in some cases they may hire a lawyer to take accurate and detailed minutes of the interview.

The interview can be, and sometimes is, recorded. A transcript is usually not made; however, the employer may hire a third-party vendor to make a transcript in order for it to be used as evidence.

Although some precedents have denied the admissibility of secret recordings as evidence (eg, Tokyo High Court judgment of 19 May 2016, Jurist No 1496, p4, Employee v Kanto Gakuin), in most cases courts have found such recordings to be admissible as evidence. Recently, however, it has become common practice for interviewers to inform the interviewee that the interview is being recorded and to allow the interviewee to make their own recording upon request.

When conducting interviews remotely, it is difficult to prevent secret recordings. Even if recording functions are disabled within the web-conference system, it is hard to prevent participants from recording the interview using external devices such as smartphones. The following measures can be considered as possible responses:

  • establishing rules in advance prohibiting all recording or filming;
  • warning the participants that the secret recording and leakage of the information is strictly prohibited, in order to handle the confidential information properly; and
  • taking into account the possibility of secret recordings when making statements.

In addition to interviews, the investigator must examine objective evidence and the relevant documents and internal communications. Based on the precedent case law (Tokyo District Court judgment of 26 February 2002, Roudou Hanrei Vol 826, p50, Employee v Nikkei Quick), the employer may review company account email communications during the internal investigation. The employer may also instruct the employee to submit the company-issued laptop and mobile phone for analysis by a third-party forensic service vendor.

However, the employer should be careful not to violate privacy unrelated to the investigation, and any communication through a private email address cannot be accessed even if the communication was through the employer’s laptop or mobile phone. Moreover, the employee’s locked locker and desk cannot be forcibly opened without their consent.

It rarely happens, but the employer can request Preservation of Evidence (Article 234 of the Code of Civil Procedure) in order to preserve the necessary evidence.

An employer may (and should) take action to protect the reporter, based on the reporter’s wishes. Typically, the employer may take HR measures, including permissions and/or instructions for the victim and/or the perpetrator, relocation and transfer.

If the employer fails to take appropriate measures and the employees suffer damage caused by such failure, the employer will be legally liable as it has a duty of care towards its employees based on Article 5 of the Labour Contracts Act. In the case of the whistle-blowing in particular, the employer must take measures to ensure that the whistle-blower will not suffer any disadvantages because of the report. At the same time, the employer should be mindful that such action may inadvertently reveal specific information about the victim and the whistle-blower.

The employer may take action to protect the respondent, if the employer deems such action necessary based on its duty of care to its employees. By way of example, the investigation team should be careful not to engage in inappropriate behaviour, including coercion, duress, threats, fraud and harm to the respondent’s human rights and health. However, excessive protective measures may create the perception that the employer is attempting to cover up the matter, support the perpetrator and/or overprotect the respondent.

The employer does not usually take disciplinary action against the respondent before the conclusion of an HR internal investigation. Overlapping disciplinary action for the same misconduct is prohibited and the court will invalidate such action (Article 15 of the Labour Contracts Act); therefore, the employer usually awaits the conclusion of an HR internal investigation. If necessary and there is clear evidence of legal violations or breaches of the Work Rules, the employer may take HR measures ‒ including a warning letter, instruction notice, demotion, relocation or transfer – with regard to the respondent in order to prevent further misconduct, which is different from disciplinary action.

As the employer has a duty of care to its employees based on Article 5 of the Labour Contracts Act, the employer may (and should) take measures to protect other employees if it is foreseeable that they may suffer harm. By way of example, in the case of harassment, the employer may take HR measures (including a warning letter, instruction notice, demotion, relocation or transfer) with regard to the respondent. If the employer fails to take appropriate measures and – the employees suffer damage due to such failure, the employer will be legally liable. On the other hand, the person subject to such action can argue that such action is invalid owing to an abuse of rights (Article 3, paragraph 5 of the Labour Contracts Act).

There are no procedural guarantees that must be established, nor steps that must be followed in HR internal investigations in Japan. However, at the beginning of the interviews, it is advisable for the interviewer to explain the matters mentioned in 3.7 Information.

The employer may have internal regulations regarding an HR internal investigation. In some cases, there are stipulations in relation to the investigation, such as:

  • an obligation to follow instructions of the employer and the supervisor (including the investigation);
  • an obligation to return company-issued items (eg, laptop, mobile phone);
  • consent to inspection of emails issued by the employer; and
  • an obligation to work from home if instructed (throughout the investigation).

However, as detailed rules and descriptions will bind the employer and limit flexible treatment, the company tends not to specify further details.

In judicial practice, the party seeking a specific outcome bears the burden of proof. There are no specific rules regarding the burden of proof for an HR internal investigation, but the investigation team generally bears the burden of proof and should substantiate the allegations and the subject of the investigation. If the investigation team establishes a prima facie case, the burden of proof may shift, at least partially, to the other party (eg, the obligation to provide a legitimate reason or provide an alibi). It is generally accepted that the “balance of probabilities” serves as the standard of proof in civil cases, whereas “beyond any reasonable doubt” is employed in criminal cases.

When the employer takes action based on the investigation findings, the investigator should carefully consider the degree of proof required using a standard closer to “beyond any reasonable doubt”. On the other hand, if the report’s sole purpose is for managerial decision-making, the investigator should apply a standard closer to the “balance of probabilities” while endeavouring to incorporate the maximum number of facts into the report.

There are no rules governing when an HR internal investigation can be ended. Typically, an HR internal investigation concludes when the team has found sufficient evidence to close the case or when it determines that it is unable to gather sufficient evidence.

There are no specific procedures to follow when deciding to close an HR internal investigation. However, especially in the case of a written whistle-blowing report, it is necessary to notify the whistle-blower of the outcome of the response to the report succinctly. It is also common practice to share this information with the relevant party, such as the victim. With regard to whistle-blowing reports, as mentioned in 2.1 Communication to the Reporter and the Respondent, it is recommended that the employer informs the whistle-blower if it decides not to initiate an investigation at an early stage.

There are no specific rules on the form that the conclusion must take, but it is common practice for the investigation team to submit the investigation report to the HR department or the board of directors. If a listed company carries out an investigation, it may disclose the report or its summary through a press release. Furthermore, if the results of the investigation are related to government regulation, the employer may contact the relevant authority with the corrective and preventative measures. If the investigation committee wishes to comply with the “Third-Party Committee Guidelines for Corporate Scandals” issued by the Japan Federation of Bar Associations, the draft of the investigation report should not be disclosed to the client before the report is finalised.

There are no specific requirements regarding what information should be included in the investigation report. Typically, the investigation report includes:

  • the investigation’s subject, scope, measures, restrictions and limitations;
  • the results of the fact-finding;
  • the legal analysis, rationale and grounds for the matter; and
  • corrective and preventative measures.

As the purpose of the investigation is to serve and support managerial decisions and business judgements, all important matters (including the next steps) found by the investigation team will be broadly included in the report.

The relevant parties do not have the right to receive information regarding the outcome of an HR internal investigation. However, according to the government circular notice relating to the Whistle-Blower Protection Act, the employer will usually report in brief the results and the corrective measures to the whistle-blower promptly, taking into consideration the privacy protection of the relevant parties. In addition, if the employer wishes to proceed with the investigation based on the “Third-Party Committee Guidelines for the Corporate Scandal”, the investigation report submitted by the third-party committee should be promptly disclosed to the relevant stakeholders concerned with the misconduct.

Employers are not required to report the conclusion of an HR internal investigation to the authorities. However, the employer must report certain types of personal information leakage to the Personal Information Protection Commission (see 2.2 Communication to Authorities). Furthermore, if the employer finds a violation of antitrust laws, the employer may consider filing a “leniency” report with the Japan Fair Trade Commission in order to mitigate the expected sanction. In addition, the employer may voluntarily report to the authorities (eg, the regulatory authorities, the police or the public prosecutor’s office), if such report will be advantageous and beneficial.

It is common practice to prepare and organise a detailed report and evidence before filing it; however, the employer should take into account the deadline and the existence of other reporters at the same time.

There are no other parties that must be informed of the conclusion of an HR internal investigation. If the conclusion of an HR internal investigation is important for managerial decisions, the investigation team usually communicates the conclusion to the relevant managers, including the representative director or the board of directors. However, in the case of a whistle-blowing report, the team should be careful not to share information concerning the whistle-blower outside the team.

Based on the conclusion of the investigation, the employer may consider taking disciplinary action or HR action against the relevant party who is in violation of the law or the internal rules. However, the employer must stipulate in advance the nature and the grounds for the disciplinary action (including dismissal) in the employment contract or the Work Rules, and the employer should comply with these provisions.

Before any disciplinary action is taken, it is common practice to hold a hearing to allow the subject of the action to provide their excuse or explanation. The employee subject to the disciplinary action and the dismissal may contest its validity through litigation or a labour tribunal procedure, and the judge may invalidate the company’s action if they find an abuse of rights (Articles 15 and 16 of the Labour Contracts Act).

There are no specific standards for employer action following an HR internal investigation. However, if the allegations of the reporter or the victim are at least partially true, the employer usually warns the perpetrator to refrain from engaging in similar conduct and emphasises that any retaliatory action against the victim or whistle-blower will not be tolerated. In addition, if the employer believes that a transfer, relocation or demotion is necessary or beneficial, the employer will take such HR action internally.

An employer may collect personal data for the purpose of an HR internal investigation. However, as the investigation will conflict with the protection of privacy, the employer should consider the balance and proportionality between the necessity and the extent of collecting the information. In addition, special care-required personal information ‒ which includes race, trust, social status, medical records, crime records and victim records – is strongly protected under the Act on the Protection of Personal Information (Article 2, paragraph 3) and the acquisition of such information is prohibited without consent, with a few exceptions.

An employer should act in accordance with the Act on the Protection of Personal Information, as mentioned in 7.1 Collecting Personal Data. In addition, the investigation team should follow the Work Rules and internal rules on the protection of personal information.

The owner of the personal data has the right to access and correct the personal data collected in the course of an HR internal investigation (Article 34 of the Act on the Protection of Personal Information). However, this right cannot be used to change the results of the fact-finding or the investigation report.

AI serves as a supplementary tool in conducting internal investigations. For example, AI is utilised to conduct digital forensics on data held by the respondent, such as extracting, organising and rapidly reviewing large volumes of emails and documents. AI is also used to transcribe audio recordings from interviews conducted with the respondent and relevant parties. On the other hand, factual findings and legal assessments continue to be made by the investigation team (lawyers).

Even when AI is used in internal investigations, the handling of employees’ personal data requires appropriate protection and consideration for privacy, as described in 7.1 Collecting Personal Data, and the use of AI needs to comply with the company’s internal investigation rules, information management policies, data protection policies and other relevant internal regulations. In addition, to prevent the leakage of confidential information, it is necessary to implement security measures, such as using a closed-environment AI or configuring the AI to preclude learning from the input data.

The Whistle-Blower Protection Act contains detailed provisions for the protection of whistle-blowers. The subject of the protection is a whistle-blower who is an employee, a former employee who retired from the employer within one year, or a business partner and their employees and officials (Article 2, paragraph 1). The subject of the whistle-blower’s report is a violation of the laws concerning the protection of the life, body, property and other rights of the citizen, which involves criminal and/or unlawful conduct subject to criminal sanctions and fines; such laws (of which there are more than 500) are listed in the Whistle-Blower Protection Act (Article 2, paragraph 3). The destination of the report is categorised into three types ‒ namely, employers, authorities and other organisations ‒ and the requirements for protection differ for each type. Pursuant to the Whistle-Blower Protection Act, adverse treatment, retaliation, dismissal and any claim for damage against the whistle-blower based on the whistle-blower report are prohibited (Articles 3, 5, 6 and 7 of the Whistle-Blower Protection Act).

The employer should take preventative measures against sexual harassment (Article 11, paragraph 1 of Act No 113 of 1972 – the “Act on Equal Opportunity and Treatment Between Men and Women in Employment”). If the employer fails to take appropriate measures, it will be in violation of its duty of care, which exposes the employer to legal risks. Sexual harassment is defined as “acts in the workplace that cause an employee to suffer disadvantages in their working conditions or harm to their work environment due to sexual conduct, and the employee’s response to such sexual conduct” (Article 11, paragraph 1).

The government guidelines provide for two types of typical sexual harassment ‒ ie, quid pro quo sexual harassment and hostile work environment sexual harassment.

In June 2025, an amendment to the Act on Equal Opportunity and Treatment Between Men and Women in Employment mandating employers to take necessary measures to prevent sexual harassment against job applicants was promulgated. The amendment is scheduled to enter into force by December 2026.

The employer is obligated to take preventative measures against harassment in relation to maternity, childbirth, childcare and nursing care (Article 9, paragraph 3 and Article 11-3 of the Act on Equal Opportunity and Treatment Between Men and Women in Employment, and Article 10 and Article 25, paragraph 1 of Act No 76 of 1991 – the “Act on Childcare Leave, Caregiver Leave, and Other Measures for the Welfare of Workers Caring for Children or Other Family Members”).

In addition, the Guidelines issued by the Ministry of Health, Labour and Welfare (MHLW) clarify that harassment towards same-sex individuals and/or gender minorities is included within the scope of sexual harassment, as referred to in 8.2 Sexual Harassment and/or Violence. Such harassment is known as “SOGI (sexual orientation, gender identity) Harassment”, and the employer should take preventative measures against it.

Furthermore, the MHLW Guidelines make it clear that an “outing” or an unwilling disclosure of sexual orientation and gender identity is considered power harassment due to its nature as a violation of the right to personal privacy. Bullying and mobbing are considered “power harassment” in Japan, which the employer should take preventative measures against (Article 30-2, paragraph 1 of Act No 132 of 1966 – the “Act on Comprehensively Advancing Labour Measures, and Stabilising the Employment of Workers, and Enriching Workers’ Vocational Lives”). Power harassment is defined as “behaviour in the workplace that is based on a superior relationship and exceeds the necessary and reasonable scope of work, resulting in harm to the employee’s working environment”.

The government guidelines provide an appropriate list for such preventative measures, and the employer must adopt such measures in the workplace. If the employer fails to take appropriate measures, it would constitute a breach of its duty of care and consequently expose it to legal risks.

The above-mentioned Act was amended to expand employer obligations to take measures against “customer harassment”, which means abusive or unreasonable behaviour by customers toward employees. Employers are expected to set up complaint mechanisms, revise workplace rules and conduct preventative training under the revised legislation. The amendment was promulgated in June 2025 and is scheduled to enter into force by December 2026.

There are no specific procedures that the employer must follow if the allegation is also criminal in nature, but the employer may consider consulting with the appropriate authority, if necessary. For example, if a legal violation has been identified regarding criminal activity, corrective measures will be required and, depending on the circumstances, the employer will consider whether it will submit the criminal complaint and/or other report to the authorities. On the other hand, the employer should be careful to check the facts and evidence in order to avoid committing the offence of false accusation.

In addition, reporting to the authorities may trigger an investigation, which can impose a significant burden on the company, create reputational risks and result in media exposure. The governmental authorities may not stop the investigation proceedings, even after the employer repeals the criminal complaint. Furthermore, the investigation may reveal facts that were previously unknown, potentially leading to unforeseen outcomes. In light of these considerations, it is advisable for the company to carefully determine whether to consult or report the matter to the authorities.

There are no specific procedures that an employer should follow in a multi-jurisdictional case; the investigation team should consider the applicable laws, conflicts of law, the applicability of the contracts, the Work Rules and other internal rules. In addition, the provision and transfer of personal information outside Japan is restricted under the Act on the Protection of Personal Information (Article 28), so the investigation team should pay attention to such regulations.

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Law and Practice

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AI-EI Law Firm was established in 2019, mainly by lawyers from Nishimura & Asahi, and specialises in corporate dispute resolution and labour/employment matters. The name “AI-EI” is derived from the Japanese word “相栄” (pronounced “I-A”), which means collective prosperity. To achieve collective prosperity with its clients, the firm takes the unrivalled approach of not only accurately analysing and categorising a large amount of past data (in this case, vast experience and knowledge), like AI does, but also using elements of EI (emotional intelligence) so that clients’ true needs are properly understood. Thus, clients are guaranteed practical solutions that address the substance of the dispute – not only from the perspectives of “economic rationality” and “efficiency” required in business, but also with the humanity and sensitivity required when dealing with people who are the subjects and the objects of disputes and labour issues.

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