In fact, CET-4 and CET-6 can also test Japanese. Of course, you can also choose Japanese as a foreign language in college. As for whether to choose Japanese, or whether you are interested in it for the time being, you should consider it thoroughly.
Because you need CET-4 and CET-6 for subsequent graduation, it is difficult to graduate if you fail CET-4, so you should choose Japanese carefully, because you have studied English for at least six years.