When diplomatic relations become strained, animals, especially exotic ones, can come to the rescue. This is particularly true of giant pandas.

Shin Shin, a giant panda on loan from China to Tokyo's Ueno Zoo, is currently the object of great expectations.

Giant panda Shin Shin munches bamboo in her cage at Tokyo's Ueno Zoo. Shin Shin is showing signs of being pregnant, the zoo said. Yoshikazu TSUNO / Agence France-Presse

The zoo removed Shin Shin from public view on Tuesday because she shows signs of pregnancy. Shin Shin's male partner, Ri Ri, remains on display.

Caretakers noticed that Shin Shin has been sleeping more, has less appetite and shows higher hormone levels. All are signs that she might be pregnant.

The zoo has installed four monitors in Shin Shin's delivery room. Chinese experts from Ya'an, Sichuan province, will come, though the schedule is not decided yet.

Japan has eight giant pandas, including the pair in the Ueno Zoo.

Last year, Shin Shin gave birth on July 5, the first time in 24 years that the zoo had a baby panda. But the cub died of pneumonia six days later.

Now the zoo is doing everything it can to conducive to a successful pregnancy, including preventing noise-related stress.

Shin Shin and Ri Ri were borrowed from the Chinese government in friendlier times, back in February 2011.

Giant pandas have been enormously popular in Japan since they began serving as adorable diplomats in 1972.

In 1972, China gave Japan two 2-year-old giant pandas - one female and one male - as a gift to observe the normalization of their diplomatic relations. The two never had cubs.

The possibly pregnant Shin Shin has received best wishes from both China and Japan.

Foreign Ministry Spokesman Hong Lei said he hopes the panda will grow healthy. Japan's chief government spokesman, Yoshihide Suga, said: "If it's true, it would be very welcome. I hope it is so."

Meanwhile, the war of words continues between the two nations. The Japanese government denies the consensus the leaders of the two countries reached in 1972 to leave the issue of the Diaoyu Islands on the back burner.

To mend Sino-Japanese relations, former Japanese lawmaker Hiromu Nonaka is visiting Beijing as head of a nonpartisan group of current and former Japanese lawmakers that include former Liberal Democratic Party secretary-general Makoto Koga.

The two countries are expected to observe the 35th anniversary of their Treaty of Peace and Friendship this year.

If Shin Shin gives birth, it will be an opportunity to help re-ignite Japan's popular goodwill toward China.