It is the Meiji era. Satoko is born of a prestigious family and blessed with great beauty, but she is sickly and is said to have a limited life expectancy, so her only dream is… a convenient marriage to benefit her family. But suddenly, she is targeted by a mysterious assassin...!? Trying to survive, Satoko makes a desperate "proposal" to the killer...!? A high-class lady and an assassin... A suspenseful love story about a contract marriage between two people who never should've met!