In Japan, the concert will be held earlier than in the US and Europe　May 26, 2020

The Japanese government lifted a state of emergency declaration on May 25, ahead of schedule, over a new coronavirus infection that had been set to run until May 31, 2020.

(PM) Abe said the government will be gradually easing restrictions on events such as concerts, starting with a cap of 100 audience members and gradually increasing it to 1,000, 5,000 and then 50 percent capacity. The country needs to change its approach from not holding events to considering how to hold events while reducing infection risks, he said.

Japan cautiously lifts last of virus emergency controls [Japan Times MAY 25, 2020]
https://www.japantimes.co.jp/news/2020/05/25/national/japan-lifts-state-of-emergency-coronavirus/#.XsyeahP7TOQ

Specifically,

• May 25 to June 18, 2020:
  Indoors, no more than 100 people or no more than 50% of the capacity
  Outdoors, no more than 200 people. The distance between people must be 2 meters (6.56 ft.).
• June 19 to July 9, 2020:
  No more than 1,000 people or 50% of the capacity, both indoor and outdoor.
• July 10 to July 31, 2020:
  No more than 5,000 people or 50% of the capacity, both indoor and outdoor.
• On or after August 1, 2020:
  Infection status will be examined and every prefectures will be notified again by the Government.

This means that it looks like the concert in Japan will take place earlier than in the US or Europe.