Set in the not too distant future where it is commonplace for high tech crimes to get through cyber defense, Iwase Shobei (Nakamura Baijaku), a man of great wealth who is also a well-known collector of gems, asks private investigator Akechi Kogoro (Nagayama Kento) to provide personal protection for his daughter Sanae (Fukumoto Riko). Iwase has been warned that she will be kidnapped. The mysterious phantom thief Kurotokage, who has a reputation for deftly replacing precious gems with imitations, stands in Akechi's way. However, Kogoro catches on that Madam Midorikawa (Ryo), the owner of an exclusive hotel who has come forward to give shelter to Sanae, is actually Kurotokage, and prevents Sanae's abduction. However, he is hampered by a trick laid in the entire hotel and fails to catch her. However, at that moment, the thief and famous investigator secretly fall in love. Akechi chases Kurotokage and eventually learns about her tragic past and surprising identity. Although they are swayed by forbidden love, the two of them have a final showdown at Kurotokage's secret museum which houses her collection. Who will be the victor?
—Jdrama Weblog