In order to ensure that an adequate level of data protection is guaranteed also in practice, an independent supervisory authority tasked with powers to monitor and enforce compliance with the data protection rules should be in place. This authority should act with complete independence and impartiality in performing its duties and exercising its powers.

In Japan, the authority in charge of monitoring and enforcing the APPI is the PPC. It is composed of a Chairperson and eight Commissioners appointed by the Prime Minister with the consent of both Houses of the Diet. The term of office for the Chairperson and each of the Commissioners is five years, with the possibility for reappointment (Article 64 of the APPI). Commissioners may only be dismissed for good cause in a limited set of exceptional circumstances (57) and must not be actively engaged in political activities. Moreover, under the APPI, full-time Commissioners must abstain from any other remunerated activities, or business activities. All Commissioners are also subject to internal rules preventing them from participation in deliberations in case of a possible conflict of interests. The PPC is assisted by a Secretariat, led by a Secretary-General, that has been established for the purpose of carrying out the tasks assigned to the PPC (Article 70 of the APPI). Both the Commissioners and all officials in the Secretariat are bound by strict rules of secrecy (Articles 72, 82 of the APPI).

According to the case law of the Court of Justice (147), and as recognized in Article 45(4) of Regulation (EU) 2016/679, the Commission should continuously monitor relevant developments in the third country after the adoption of an adequacy decision in order to assess whether Japan still ensures an essentially equivalent level of protection. Such a check is required, in any event, when the Commission receives information giving rise to a justified doubt in that respect.

Therefore, the Commission should on an on-going basis monitor the situation as regards the legal framework and actual practice for the processing of personal data as assessed in this Decision, including compliance by the Japanese authorities with the representations, assurances and commitments contained in Annex II. To facilitate this process, the Japanese authorities are expected to inform the Commission of material developments relevant to this Decision, both as regards the processing of personal data by business operators and the limitations and safeguards applicable to access to personal data by public authorities. This should include any decisions adopted by the PPC under Article 24 of the APPI recognising a third country as providing an equivalent level of protection to the one guaranteed in Japan.

Moreover, in order to allow the Commission to effectively carry out its monitoring function, the Member States should inform the Commission about any relevant action undertaken by the national data protection authorities ("DPAs"), in particular regarding queries or complaints by EU data subjects concerning the transfer of personal data from the European Union to business operators in Japan. The Commission should also be informed about any indications that the actions of Japanese public authorities responsible for the prevention, investigation, detection or prosecution of criminal offences, or for national security, including any oversight bodies, do not ensure the required level of protection.