[Opinions] Re: Can a Chinese person use a Japanese name?
First, be aware that Arata sounds very close to erotic and errata. Neither of those is especially good as a name element.
Second of all, is Arata a given name in Japanese culture, and what are its connotations there? If it's strictly a surname, for instance, you will be seen as, maybe not insensitive, but definitely silly, if and when you encounter someone of Japanese culture or who is well-educated in all things Japanese.
Also, given the history of relations between Japan and China for quite some time, it's a bit odd to think of a Chinese person deliberately giving their child a Japanese name. This probably isn't as true in the US or other places outside China or a large Chinese community, but it is something to think about.
As to what other names you can use, well, that's up to you. You could use a Chinese name, maybe one that means the same as Arata? (Not just one that sort of sounds like it unless you are very fluent in the language.)
Or you could use a name used popularly in the culture where you live now. It is impossible to guide you further since you've given no other parameters.
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Steve Martin