How old are Sina and Zimu stars for me?

I didn't say how old. Stars, to me, are written by crayon dogs. When Mu Zi Xing was five years old, a beautiful boy-Xina suddenly appeared in her life and became her childhood friend. When we first met, we were playing with mud and were rejected by Sina. We feel very annoying, but we don't know that this cold and ugly teenager around us has always been attracted by her cheerful and smiling face, and this mood is getting deeper and deeper with age.