Moreover, under Article 16(1) of the APPI, PIHBOs are prohibited from handling personal information beyond the "necessary scope to achieve a utilization purpose" specified under Article 15 without obtaining in advance a data subject's consent, unless one of the derogations in Article 16(3) applies (27).

Subsequently, as explained in recitals 41 and 42, the PIHBO is prohibited from processing the personal information for other purposes, except where the data subject consents to such processing or where one of the derogations pursuant to Article 16(3) of the APPI applies.

As regards transfers from the European Union, personal data will necessarily have been first collected and processed in the EU in compliance with Regulation (EU) 2016/679. This will always involve, on the one hand, collection and processing, including for the transfer from the European Union to Japan, on the basis of one of the legal grounds listed in Article 6(1) of the Regulation and, on the other hand, collection for a specific, explicit and legitimate purpose as well as the prohibition of further processing, including by way of a transfer, in a manner that is incompatible with such purpose as laid down in Articles 5(1)(b) and 6(4) of the Regulation.

These principles are ensured in Japanese law by Article 16(1) of the APPI, which prohibits the handling of personal information beyond "the necessary scope to achieve a utilisation purpose". As explained by the PPC, this not only excludes the use of data that is not adequate and the excessive use of data (beyond what is necessary for achieving the utilisation purpose), but also entails the prohibition to handle data not relevant for the achievement of the utilisation purpose.

According to Article 19 of the APPI, PIHBOs are required to "strive […] to delete the personal data without delay when such utilisation has become unnecessary". That provision needs to be read in conjunction with Article 16(1) of the APPI prohibiting the handling of personal information beyond "the necessary scope to achieve a utilisation purpose". Once the utilisation purpose has been achieved, processing of personal information cannot be considered necessary anymore and, hence, cannot continue (unless the PIHBO obtains the data subject's consent to do so).

A first protection is enshrined in Article 24 of the APPI which generally prohibits the transfer of personal data to a third party outside the territory of Japan without the prior consent of the individual concerned. Supplementary Rule (4) ensures that in the case of data transfers from the European Union such consent will be particularly well informed as it requires that the individual concerned shall be "provided information on the circumstances surrounding the transfer necessary for the principal to make a decision on his/her consent". On that basis, the data subject shall be informed of the fact that the data will be transferred abroad (outside the scope of application of the APPI) and of the specific country of destination. This will allow him/her to assess the risk for privacy involved with the transfer. Also, as can be inferred from Article 23 of the APPI (see recital 47), the information provided to the principal should cover the compulsory items under its paragraph 2, namely the categories of personal data provided to a third party and the method of disclosure.

Although not all provisions of Chapter IV, Section 1 of the APPI are listed in Article 42(1) – which also determines the scope of application of Article 42(2) – this can be explained by the fact that certain of those provisions do not concern obligations of the PIHBO (59) and that all essential protections are already afforded by other provisions that are included in that list. For instance, although Article 15 (requiring the PIHBO to set the utilisation purpose and process the relevant personal information exclusively within its scope) is not mentioned, failure to observe this requirement can give ground to a recommendation based on a violation of Article 16(1) (prohibiting the PIHBO to process personal information beyond what is necessary to achieve the utilisation purpose, unless it obtains the data subject's consent) (60). Another provision not listed in Article 42(1) is Article 19 of the APPI on data accuracy and retention. Non-compliance with that provision can be enforced either as a violation of Article 16(1) or based on a violation of Article 29(2), if the individual concerned asks for the correction or deletion of erroneous or excessive data and the PIHBO refuses to satisfy the request. As regards the rights of the data subject according to Articles 28(1), 29(1) and 30(1), oversight by the PPC is ensured by granting it enforcement powers with respect to the corresponding obligations of the PIHBO laid down in those Articles.

Importantly, Article 21(2) of the Constitution guarantees the secrecy of all means of communication, with limitations only allowed by legislation on public interest grounds. Article 4 of the Telecommunications Business Act, according to which the secrecy of communications handled by a telecommunications carrier shall not be violated, implements this confidentiality requirement at the level of statutory law. This has been interpreted as prohibiting the disclosure of communications information, except with the consent of users or if based on one of the explicit exemptions from criminal liability under the Penal Code (77).

As regards the interception of communications, Article 3 of the Wiretapping Act authorises such measures only under strict requirements. In particular, the public authorities have to obtain a prior court warrant that may only be issued for the investigation of specific serious crimes (listed in the Annex to the Act) (85) and when it is "extremely difficult to identify the criminal or clarify the situations/details of the perpetration by any other ways" (86). Under Article 5 of the Wiretapping Act, the warrant is issued for a limited period of time and additional conditions may be imposed by the judge. Moreover, the Wiretapping Act provides for a number of further guarantees, such as for instance the necessary attendance of witnesses (Articles 12, 20), the prohibition to wiretap the communications of certain privileged groups (e.g. doctors, lawyers) (Article 15), the obligation to terminate the wiretapping if it is no longer justified, even within the period of validity of the warrant (Article 18), or the general requirement to notify the individual concerned and allow access to the records within thirty days after the wiretapping has been terminated (Articles 23, 24).

Finally, the PSIA may carry out investigations under the Subversive Activities Prevention Act ("SAPA") and the Act on the Control of Organisations Which Have Committed Acts of Indiscriminate Mass Murder ("ACO") where such investigations are necessary to prepare the adoption of control measures against certain organisations (126). Under both Acts, upon request by the Director-General of the PSIA the Public Security Examination Commission may issue certain "dispositions" (surveillance/prohibitions in the case of the ACO (127), dissolution/prohibitions in the case of the SAPA (128) and in this context the PSIA may carry out investigations (129). According to the information received, these investigations are always conducted on a voluntary basis, meaning that the PSIA may not force an owner of personal information to provide such information (130). Each time, controls and investigations shall be conducted only to the minimum extent necessary to achieve the control purpose and shall not under any circumstances be carried out to "unreasonably" restrict the rights and freedoms guaranteed under the Constitution of Japan (Article 3(1) of SAPA/ACO). Moreover, according to Article 3(2) of the SAPA/ACO, the PSIA must under no circumstances abuse such controls, or the investigations carried out to prepare such controls. If a Public Security Intelligence Officer has abused his/her authority under the respective Act by forcing a person to do anything which the person is not required to, or by interfering with the exercise of a person's rights, (s)he may be subject to criminal sanctions pursuant to Article 45 SAPA or Article 42 ACO. Finally, both Acts explicitly prescribe that their provisions, including the powers granted therein, shall "not under any circumstances be subject to an expanded interpretation" (Article 2 of SAPA/ACO).

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.