The story tells about a 22-year-old beauty named Ichika (Alice Hirose) who got a 5 trillion yen inheritance from her late father. As a result, she was targeted by her father's brothers and sisters who wanted to kill her and take the money. In order to protect her, the housekeeper Hashida Masako (Miki Mizuno) who lives with her hired the famous detective Chikumagawa Hikaru (Kenichi Takito). He is elusive and paranoid. He will uncover the assassin's conspiracy before he carries out his murder plan, and will also explain his tricks and fight back, bringing a "no crime, no murder" mystery drama.