He is her spiritual pet, coming to her across thousands of years.
He remembers their past, but she has already entered reincarnation, and has no memory of the past. She has always been his master, and he is just her spiritual pet cat.
A mysterious picture and an ancient tree gave him a chance to finally find her and come to her world.
In the first two lives, they were separated by yin and yang, but in this life, will they have different endings?