"The uncertainty (about what the frog will do) interests me," Zhou says.

"Even if in the same trip about one particular site, the photos are slightly different. For instance, sometimes, he's facing the camera. Sometimes, the shot is of the back of his head."

Zhou－like many players－worries about the frog when he travels for long periods of time. She often checks to see if he has returned or at least sent photos.

Her frog recently made a friend, to her delight. Two recent photos show the amphibian staring at a giant tree with a mouse.

"He's a cool frog," she explains.

"You can't control him. He has his own ideas and does whatever he likes. You can only pack his bags and observe him from afar. When I have a child, I'll treat him like this. I'll respect him as an individual and encourage him to make his own decisions.

"The frog is just like me. Playing the game is like viewing a reflection of part of myself."

Zhou enjoys traveling and often takes trips on her own.

She also decides to hit the road spontaneously. And she often buys postcards and local specialties.

Zhou felt a connection with the frog when she purchased postcards and snacks while visiting Fujian province's Xiamen recently.

She plans to visit the same Japanese destinations as her frog and take similar photos.

Players often share experiences.

"I want to know where the frog has been and what kind of photos he has sent back," 32-year-old Xiao Lixin says.

"I'll discuss it with friends. I've become that kind of so-called annoying mother, comparing my frog with others'. I worry when he travels. But when he's home, I wonder why he doesn't go out to have fun."

Players often see themselves in their frogs, she points out. For instance, hers likes delicious food.

Pan Jing, who studied in Japan for a year and now lives in Beijing, says: "It reflects the Japanese philosophy of living your own life and not bothering others. The frog isn't at all fussy. He can travel with whatever you pack and enjoy the pretty views along the way."

The 30-year-old, who has a 4-year-old daughter, points out many players don't have kids.