Based on time zones (Japan is 13 hours ahead), and considering Lighthizer left on Thursday; it would appear Japanese Economy Minister Toshimitsu Motegi and U.S. Trade Representative Robert Lighthizer are meeting right about now.
(Reuters) – Japanese Economy Minister Toshimitsu Motegi said on Friday that he will meet with U.S. Trade Representative Robert Lighthizer in Tokyo on Saturday for trade talks ahead of a summit meeting between leaders from the two nations on Monday.
Japanese Prime Minister Shinzo Abe and U.S. President Donald Trump are expected to discuss topics including North Korea’s nuclear programs, trade issues and the coming Group of 20 leaders’ summit. (link)
Following the State Dinner to celebrate the beginning of the Reiwa Era, introduced with the coronation of Japanese Emperor Naruhito, President Donald Trump and Prime Minister Shinzo Abe are scheduled to hold a summit and joint press conference on Monday.
There is a rumor their presser may include a “significant announcement.”
I cannot think of a non-splendid reason for Ambassador Lighthizer to fly all the way to Japan if Trump and Abe didn’t have something planned.