How did panda travel abroad?

Few month ago, I saw a picture that a panda on airplane business class company with a guy who is take care of it. And that flight is from china to Japan.panda was an national gift to Japan. So I was wondering dose panda need apply an passport and apply an visa to entry an country? Since panda is company with people, and on an civilian airplane, I guess after panda landing, it also need to pass immigration, will panda trouble to do that? So if panda need an passport, and it must apply visa to go country such as US, which visa section panda need, immigration or non immigration? Did panda has an diplomatic passport? And diplomatic immunity?.....