Blood contract is an enthralling series that chronicles the captivating journey of Rosy, who after losing her job and her sense of purpose, meets Sam, a wealthy vampire who proposes to hire her as his contract bride. Although Rosy feels intimidated by Sam's dark world, she takes the offer, thinking that it could be her only chance to make something of her life. As Rosy navigates her new position as a contract bride, she becomes increasingly aware of the dangerous and enigmatic world of vampires, as well as the ongoing power struggle between Sam and his younger brother, Ken. The competition is centered on who deserves to inherit their family's enterprise after their father's death – a ruthless and cunning vampire leader.