Is Coke Okay?
Although cola can be any carbonated drink that uses a variety of different spices and flavorings, like Pepsi, we usually reserve the term cola exclusively for Coca-Cola. However, they treat the word very differently in Japan. As you can see, Pepsi is also marketed as a cola, which, technically, it is.
This has more to do with the fact that in Japan and other parts of Asia, the term cola is used to describe any dark-colored soft drink, as it should be. You’ll have to be explicit about which brand you want when shopping for a cola drink. Or you can say Coke and people will understand.