The answer to the question in the title is “because there are Asians”.
There are many asian scripts and they are different from each other as chalk and cheese.
The asian script posted does not seem Japanese. It is possibly Korean because of the circular figure.
See here:
https://www.lingualift.com/blog/tell-chinese-japanese-korean-apart/
It's definitely Korean. I don't know Korean but I can recognize it.
Chinese and Japanese use some of the same characters (though pronounced differently and may mean totally different things), but you can easily distinguish Japanese because it looks more "threadbare", if I had to think of a word, many less-complicated characters like simple strokes. Chinese looks more "dense" by comparison. Japanese is a mash-up of several different types of characters, kind of like if a European language used Latin, Cyrillic, and Greek characters all together to denote different sounds. That is an imperfect analogy, and does not exist, but that is about as closely as I can characterize Japanese.