There are various ways to learn or teach a foreign language. At one end, there is the direct method, and at the other end there are methods such as the bilingual methods and the grammar–translation method.
The direct method uses only the target language. This means that you would be learning Japanese using only Japanese (no translations etc. in Chinese and English). This method is mainly used in teaching; people who learn a language on their own typically use a translation dictionary at some point.
Teaching methods that take another language as a starting point (e.g. the grammar–translation method) normally use the learner's native language. Using a language that the learner does not know well, would put the learner at a disadvantage.
There is no good reason for using a language that you don't know well as a starting point for a new foreign language. This will slow you down and possibly cause confusion (e.g. when you look up translations and you misunderstand the translation). It is perfectly fine to use your native language as a starting point when learning Japanese. Of course, you will need to deal with the challenge that Japanese characters have a different pronunciation then Chinese characters that look the same.