Visitors watch the giant panda Shin Shin at Ueno Zoo, a day before giant panda couple Ri Ri and Shin Shin's return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)

Visitors watch the giant panda Shin Shin at Ueno Zoo, a day before giant panda couple Ri Ri and Shin Shin's return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)

Visitors wait to see the giant pandas Ri Ri and Shin Shin at Ueno Zoo, a day before their return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)

A visitor takes a photo of a stuffed panda while waiting to see the giant pandas Ri Ri and Shin Shin at Ueno Zoo, a day before their return to China, Saturday, Sept. 28, 2024, in Tokyo. A signboard, rear, in Japanese reads; "The admission for viewing has ended." (AP Photo/Eugene Hoshiko)

Visitors queue to see the giant pandas Ri Ri and Shin Shin at Ueno Zoo, a day before their return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)

One of visitors waits to see the giant pandas Ri Ri and Shin Shin at Ueno Zoo, a day before their return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)

Visitors wait to see the giant pandas Ri Ri and Shin Shin at Ueno Zoo, a day before their return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)

Visitors wait to see the giant pandas Ri Ri and Shin Shin at Ueno Zoo, a day before their return to China, Saturday, Sept. 28, 2024, in Tokyo. (AP Photo/Eugene Hoshiko)