When Mitsuhiro come back to overseas events?

I will come back to participate in overseas events when the governments of Japan and the other country announce that there are no special restrictions or demands.

Ministry of Foreign Affairs of Japan

Phased Measures for Resuming Cross-Border Travel | Ministry of Foreign Affairs of Japan (mofa.go.jp)

Measures to restrict entry of Japanese nationals and travelers from Japan into countries and regions related to the new coronavirus and conditions and restrictions on entry into Japan

U.S. EMBASSY ＆CONSULTATES INCONSULTATES IN JAPAN

COVID-19 Information – U.S. Embassy & Consulates in Japan (usembassy.gov)