ai, a special fraud investigator in the investigation division, has been trying to make contact with the "land shark" group that has been causing a stir lately. after working at a snack bar used for business talks by the group for a month, she finally manages to catch their tail. however, when she is proposed to infiltrate the investigation by impersonating the female owner of a famous old inn called "yukawa house" that the group is targeting, she begins her undercover investigation. a 100 billion yen case, an absolute failure, but in the final stage of revealing the whole picture, the developer who appeared in front of ai as the buyer was her husband.
