Mukojima Sakutaro belongs to life insurance company Seiwa Life's Insurance Assessment Department. He probes all kinds of cases such as murders for insurance money, hospital insurance scams, and payments to false claimants and suicide victims, with the investigator Kisaragi Hiro to determine if payouts should be made. One day, he attends the funeral service for Yokomura Kazuki, a senior at his company. While there, he notices a woman in mourning clothes. She is Sasakura Akiko … … One month ago, Mukojima was involved in a case in which a car plunged from a cliff, killing a couple and their two children. Only the wife's mother, Chikusa, was saved. The beneficiary of the husband's insurance payout was the wife, but because both his wife and children had died at the same time, his wife's parents will be paid the money. However, if the husband had died later than his wife, it would have been allocated to his parents. The fate of the insurance payout hinges on the order in which the lives were lost in the accident. Why does Chikusa have little to say? The husband's parents ask for a reinvestigation of the circumstances of the accident. A twisted parent-child love and the family's last moments emerge while Mukojima studies the case with Ono Keigo.