The collection of personal information for national security purposes is subject to several layers of oversight from the three branches of government.
First, the Japanese Diet through its specialised committees may examine the lawfulness of investigations based on its powers of parliamentary scrutiny (Article 62 of the Constitution, Article 104 of the Diet Law; see recital 134). This oversight function is supported by specific reporting obligations on the activities carried out under some of the aforementioned legal bases (133).
Second, several oversight mechanisms exist within the executive branch.
As regards MOD, oversight is exercised by the Inspector General's Office of Legal Compliance (IGO) (134) that has been established based on Article 29 of the MOD Establishment Act as an office within the MOD under the supervision of the Minister of Defence (to which it reports) but independent from MOD's operational departments. The IGO has the task of ensuring compliance with laws and regulations as well as the proper execution of duties by MOD officials. Among its powers is the authority to carry out so-called "Defence Inspections", both at regular intervals ("Regular Defence Inspections") and in individual cases ("Special Defence Inspections"), which in the past have also covered the proper handling of personal information (135). In the context of such inspections, the IGO may enter sites (offices) and request the submission of documents or information, including explanations by the Deputy Vice-Minister of the MOD. The inspection is concluded through a report to the Minister of Defence setting out the findings and measures for improvement (the implementation of which can again be checked through further inspections). The report in turn forms the basis for instructions from the Minister of Defence to implement the measures necessary to address the situation; the Deputy Vice-Minister is charged with carrying out such measures and has to report on the follow-up.
As regards the Prefectural Police, oversight is ensured by the independent Prefectural Public Safety Commissions, as explained in recital 135 with respect to criminal law enforcement.
Finally, as indicated, the PSIA may only carry out investigations to the extent this is necessary with respect to the adoption of a prohibition, dissolution or surveillance disposition under the SAPA/ACO, and for these dispositions the independent (136) Public Security Examination Commission exercises ex ante oversight. In addition, regular/periodic inspections (which in a comprehensive manner look at PSIA's operations) (137) and special internal inspections (138) on the activities of individual departments/offices etc. are carried out by specifically designated inspectors and may lead to instructions to the heads of relevant departments etc. to take corrective or improvement measures.
These oversight mechanisms, which are further strengthened through the possibility for individuals to trigger the intervention of the PPC as an independent supervisory authority (see below section 168), provide adequate guarantees against the risk of abuse by Japanese authorities of their powers in the area of national security, and against any unlawful collection of electronic information.