During the Taisho era, Marquess Katsukawa Masatake (played by Nagahiro) was highly renowned and respected in the financial world. Despite his glamorous life, he lamented his lack of children. Ignoring the opposition of his wife Ayako (played by Moeko Esawa), Masatake forcefully took in the lover of his bodyguard Toudou Teijinosuke (played by Hideaki Egasaki), Tohda Shinobu (played by Hitomi Kizuki), as his concubine. Soon after, Shinobu gave birth to a pair of twins. Masatake kept the boy, naming him Hiroyoshi, while the girl was taken away by her biological mother, disappearing without a trace. 19 years later, Toudou receives a letter from Shinobu and hurriedly rushes over, only to find his former lover on the brink of death. He accepts Shinobu's request to take care of her daughter, Kagami (played by Hitomi Kizuki). Kagami, as beautiful as her mother, yearns to descend into a life of prostitution. Toudou finds it impossible to stop her, and thus, Kagami's life and emotional tragedy are destined to unfold...