Thousands of people flocked to Tokyo's Ueno zoo on Sunday to see Japan's last two giant pandas, Xiao Xiao and Lei Lei, before they return to China on Tuesday. Emotional visitors stood in line for up to three-and-a-half hours for a final glimpse of the twin cubs born in 2021. Their departure marks the first time Japan will have no pandas since 1972, the year Japan and China normalized ties. Relations between Japan and China are currently tense. Japanese Prime Minister Sanae Takaichi said Japan would consider military action if China attacked Taiwan. This angered Beijing, which sees Taiwan as part of its territory. China loans pandas to countries as a goodwill gesture but retains ownership. Host countries pay about $1 million annually for each pair. Over 108,000 people tried to secure one of 4,400 spots to visit the pandas before they left. A visitor said, "I have been bringing my son here since he was a baby, so I hope it becomes a good memory for him. I'm glad we could come today to remember them." Xiao Xiao and Lei Lei were born to parents on loan from China for breeding research. Panda loans usually last about 10 years. However, a new loan to Japan is uncertain amid the current political dispute. Earlier this month, China tightened rare earth export rules to Japan, adding to the strain between the two countries.