Farewell to My Contracted Life

I'm the Smith family's adoptive son and a walking blood bank for Racquelle Smith, the heiress of the Smith family. She was born weak and has Rh-negative blood. I share her blood type, so her parents find me and use a contract to bind me to her.In exchange, they will pay for my paralyzed and bedridden sister's medical bills until she's back to normal.The contract starts when I'm ten and ends when Racquelle turns 20. The day they adopt me is the first day of the contract.Racquelle hates me, though. She thinks I'm after the Smith family's fortune and that I'm into her. She mocks and insults me for ten years, constantly calling me her dog.I react calmly, but deep down, I hate her.All I need to do is hang on for another month. I'll be free once her 20th birthday comes.