She caught his eye on his visits to Mexico City and now they are getting the honeymoon suite treatment in Tokyo.
Shuan Shuan seems to have a thing for Ling Ling
But if Ling Ling fails to show Shuan Shuan he loves her and give her the cub of which Mexico's zookeepers dream, she will be flying home next August.
Shuan Shuan has been resting at Tokyo's Ueno Zoo after her 20-hour flight.
Experts hope that Ling Ling, who was taken to Mexico three times but failed to mate there, might finally be stirred into action by a home visit.
They are encouraged by the fact that Ling Ling, 18, seemed to prefer Shuan Shuan, 16, to the two other giant female pandas at Mexico City's Chapultepec Zoo.
"She got on best with him," explained Rafael Tinajero, the
zoo's director. The two bears had, he said, showed an "interest" by making sounds and markings, as well as sniffing and looking at each other.
The sniffing and looking, however, is likely to continue for a long time yet as female giant pandas only go into heat once a year, usually in February.
Ling Ling will have to be on his paws, too, as the heat can last as little as a day and a maximum of two.
If the big day slips him by, artificial insemination will be attempted and if that succeeds the new mother will be allowed to stay in Tokyo with her new cub until the spring of 2006, when they will return to Mexico together.
Giant pandas are notoriously hard to breed in captivity and even in the wild the females normally have a cub once every two to three years.
But with an estimated total population of only about 1,000, every effort is taken to find a match.