Contract Concubine후궁 계약; Hugung Gyeyak; The Concubine Contract; El contrato de la concubina; Selir Kontrak; 後宮契約; 愛妃，你的刀掉了; Наложница по контракту

One day, Yesuh, a famous assassin, receives a strange request from a suspicious man. She's never received such a ridiculous request before, but after hearing how much the odd man was willing to pay, she decides to bite the bullet and take on the request. However, upon starting the mission, Yesuh is shocked to find out that her suspicious employer is actually--?!