The main character was adopted when she was 5 years old. Some time after that her new parents tried to adopt her twin sister but were unsuccessful. Despite that the girl grew to love her parents, especially her father. She has had many different ideas on how to repay him. Finally on her 18th birthday she decides to give her adoptive father a birthday gift, since they share the same birthday.
She tells her father that not only does she want to make love to him whenever he wants and she will give him as many children as he wants, especially after his wife had divorced him three years before and she was the one unable to have children, but she had gotten in contact with her twin sister and she was willing to have sex with him too but only to give him one child.
The main character eventually proposes marriage to her adoptive father.