The PPH pilot program between the JPO and the INPI has been in operation since January 1, 2021. The JPO recently announced that the pilot program has been extended for five years from January 1, 2025 to December 31, 2029. However, it could be further extended.
The JPO also provides helpful information to utilize the PPH based on a JPO or an INPI application.
Please refer to the following links for more details:
https://www.jpo.go.jp/e/system/patent/shinsa/soki/pph/guideline.html (in English)
https://www.jpo.go.jp/system/patent/shinsa/soki/pph/japan_france_highway.html (in Japanese)