Japanese National Phase Filings – it is not necessary to disclose all material prior art references. The JPO will consider the related art in the PCT Search Report.

Further, there is no ongoing duty to submit additional citations that you are aware of from the results of prosecution in corresponding applications in other countries. Since Japanese patent examiners will refer to corresponding application in other countries (such as, EP and US) at the time of examination, we believe that it is not necessary to submit the additional citations. Even if we do not submit citations that you are aware of, the application cannot be deemed invalid as a result.

Non-PCT Japanese Filings – if prior art references have been cited and are known at the time of filing, then it is recommended to submit them upon filing the application.
It is required to file at least one related art reference under Japanese Patent Law. The JPO may request the applicant to file citations for non-PCT applications at the time of examination if any citations were not filed at the time of filing.

The JPO may request prior art at the time of examination if no prior art was submitted.