A girl named Althea Moira Monta she eldest daughter of her family. She smart, funny, and beautiful simple senior high school girl, but her life will change. She is chosen to be The Heiress of Arguzon Empire a most powerful diamond mining company all over the world owned by her grandfather, but her life will be in danger. A man named Kim Taehyung a South Korean Mafia Boss; his family known most powerful mafia underground organization in South Korea. He given a mission to protect The Heiress of Arguzon Empire. But he fallen in love to The Heiress, he will do anything to protect her from their enemies.