Kuro no Prince: Anata no Naka no Kedamono wo Kudasai

Despite the fact that Kaede Takakura belongs to a mafia family, she keeps this a secret and spends her days as a busy detective in a small town. Then one day, a young handsome man joins the Takakura family, which is headed by Kaede's grandmother. His name is Shin Odagiri. Even though he's quiet, it's because he's lonely and kind that Kaede eventually falls for him completely. The two of them proceed to have a sweet, hot, and passionate relationship. But, those peaceful days are suddenly taken away when Kaede overhears a conversation between her boss and a mysterious cop at the police headquarters. She learns that someone is an undercover agent within the Takakura family and is spying on them. Who could this agent be...!?

(Source: Renta!)