[Machine Translation] Kajun is an understudy who is dispatched to play the role of someone who is asked to do so. When she takes on the role of a man and a woman who break up a relationship, she inadvertently mistakes the client for someone else on the job. The man who was victimized demands that Kajun pretend to be his fiancee in place of the woman who left him. She accepts to make amends, but... But, she is not only pretending to be his fiancee, she is also being taught the "bedroom etiquette" of an old family by a man of noble blood...? This is a very rich love story between a very powerful sergeant and a simple girl, and includes an extra chapter written exclusively for the bunko!