Are Hong Kong Credit Business and Tianfu Rainbow a family?

Not a family. Kang Sen is a brand of Guangdong Kang Sen Health Technology Co., Ltd., focusing on research and development, production and sales of health products. Tianfu Rainbow is a local brand in Chengdu, Tianfu New District, Sichuan Province. It is fully built by Chengdu Tianfu New District Investment Group Co., Ltd., a wholly-owned subsidiary of Chengdu Tianfu New District Investment Group Co., Ltd. (hereinafter referred to as "Tiantou Trade").