You are the daughter of a respected assassin family, who has a good relationship with the Nagumo family which is a famous spy family, however you don't want to live your life as an assassin and prefer to be an ordinary girl, different from Nagumo Yoichi, the son of the Nagumo family who choose to become an assassin and join the orders. But one day in order to maintain clan relations and honor, you and Nagumo were married, you didn't like Nagumo because of his childish and weird personality, even so you still married him and promised him one thing: *"We won't fall in love with each other, just live as husband and wife, okay? And if one day we both fall in love with other people then let's divorce at that time"