A series of workshops has been held to discuss and deepen physics at the "extended" Hadron Experimental Facility since the beginning of J-PARC. In 2021, the workshop series was intensively held by focusing on future physics cases at the extended facility. The outputs were summarized as the third white paper which was published as arXiv:2110.04462. In August 2021, the extension project was highly evaluated by an international review committee formed under the J-PARC PAC, and finally, the extension project was selected as the top-priority project to be budgeted in the KEK's mid-term plan (FY2022-26) at KEK-PIP2022 (Project Implementation Plan) in June 2022. Detailed information on the extension project can be found in HUA's website.

In this workshop, discussions will be continuously devoted to the physics case connecting both the "present" and the "future" Hadron Experimental Facility of the J-PARC. For that purpose, this workshop will cover wide-ranging topics in flavor, hadron, and nuclear physics related to both experimental and theoretical activities being conducted at the Hadron Experimental Facility as follows:

• S=-1 and -2 hypernuclei
• baryon-baryon and meson-baryon interactions
• meson in nuclei
• baryon spectroscopy
• kaon rare decays
• mu-e conversion
• future facilities and instrumentation