My husband made me his mistress's blood bank

I was born with the rarest blood group in the world, called the golden blood. My mother died at the time of delivery due to excess blood loss and my father labelled me as a taboo, and left me in an orphanage.

But, when I turned three years old, I was adopted by a wealthy person, only to donate my blood to his daughter, Mia, who happened to share the same blood group as me.

I was not a person, but a living medicine to them. Every month they drained out blood from my veins and stored them, in case their daughter suffered any mishap and needed blood.