Ryuu Mizushima is the leader of a mafia group 'Black Dragons'. Being a leader of a huge organization at a young age, he's receiving a huge responsibility and a lot of expectations from his own people. Ryuu is careful in every decision he makes since it will affect him and the Dragons. He can't afford to be reckless about everything he needs to do. And Ryuu plans that mindset to stay the same. But his world turns upside down when he meets a woman named Mara Fujisaki. The first time Ryuu met her, his inner instinct tells him that she's a living trouble. He plans to keep a distance from her to avoid any conflicts. But fate decided to start a game between him and that woman. Due to some circumstances, Ryuu finds himself being tangled with this weird and mysterious woman. Leaving him no choice, what he plans next is to keep this woman in check so she'll not bring any more trouble to him. He must keep this woman away from any trouble at all cost for the sake of his sanity and her safety. Will he be able to tame this woman? Or will it be the other way around?