What are the requirements for Chinese who want to immigrate to Japan? Do they need to become Japanese citizens?

First of all, Japan is not a country of immigration. If you have lived in Japan for 5 years and have formal tax payment records for more than 3 years, you can apply for naturalization (employed as a full member of a Japanese company). In addition, you can apply for permanent residence if you have lived in Japan for 10 years and have regular tax records for more than 5 years. (It is more difficult to work as a full-time employee in a Japanese company.) Or if you marry a Japanese and have children, you can apply for permanent residence or naturalization within 3 years.