Citizens of certain countries/regions must have a short stay visa to enter Japan.
Ministry of Foreign Affairs of Japan (MOFA)
https://www.mofa.go.jp/j_info/visit/visa/index.html

If you require a visa, we advise you to obtain and submit an official Letter of Invitation from the conference organizers to help facilitate the visa process. Please note that Letters of Invitation are only issued to registered and paid/approved attendees.

If you need an invitation letter, please contact the email below after completing your registration. (The registration site is here)

2023/4/7: At the request of Steering Committee, Organizing Committee decided to issue invitation letters to local participants as well.
If you are a student, please include your faculty advisor’s name in your invitation letter request and put the adviser in cc.
If you are not a student, please include the URL of your personal page (e.g. google scholar or dblp), a member’s page of your institution, or a published major paper page in the invitation letter request.

Contact address: pakdd2023@secretari.jp