As of October 1, 2021, In patent invalidation trials, etc., it is now possible for the applicant to appear online for an oral hearing using a web conference system.
In the past, oral hearings required both the applicant and the right holder to actually appear before the tribunal, but this has made it easier for people from far away to participate.
It also has the advantage of avoiding the risk of the recent COVID-19 infection, and is expected to be used in the future.
Ministry of Economy, Trade and Industry(METI)
https://www.meti.go.jp/press/2021/10/20211001001/20211001001.html