Another visitor told local media, crying, that she wanted to be closer to the five-year-old panda.
"Everything about her is adorable, whether sleeping or awake," she said.
Ueno Zoo receives calls and emails every day from panda fans asking it to keep Xiang Xiang, the Tokyo Shimbun daily reported, citing a zoo official.
The panda was initially set to head to China in 2021 but its departure was postponed multiple times due to travel restrictions linked to the pandemic.
In Wakayama, visitors came to say good-bye to Eimei, which became the world's oldest to father a baby panda in 2020 at age 28, the equivalent of being in his 80s for a human, as well as his twin daughters.
"Everyone is so cute I almost cried," a woman in her 70s told public broadcaster NHK.
"I'm sad they're going back to China."
The black and white mammals are immensely popular around the world and China loans them out as part of a "panda diplomacy" program to foster foreign ties.
There are an estimated 1,860 giant pandas left in the wild, mainly in bamboo forests in the mountains of China, according to environmental group WWF.
There are about 600 in captivity in panda centers, zoos and wildlife parks around the world.
