According to Kyodo News on December 6, 2016, Their Imperial Highnesses Prince Akishino and Princess Kiko  of Japan accompanied by their son, His Imperial Highness Prince Hisahito, visited Nagasaki to see:

“…relics of the 1945 U.S. atomic bombing of Nagasaki.  On his first visit to Nagasaki Prince Hisahito offered flowers at the ground zero monument in the Nagasaki Peace Park dedicated to victims of the bombing. The family also went to the Nagasaki Atomic Bomb Museum and Nagasaki Museum of History and Culture.

Atomic bomb survivor and former Nagasaki University President Hideo Tsuchiyama, 91, told of his experience to the prince, a fourth-grader at Ochanomizu University Elementary School…”