This drama is adapted from the manga of the same name. It tells the story of Oda Terutomo, whose mother died unexpectedly when he was a child. He lived with his father, who ran the Oda Group, one of the most prominent general trading companies in Japan. However, not long after his father entrusted an old key called the "Devil's Key" to Terutomo, he was killed by a mysterious man in front of him. In order to explore the secret of the "Devil's Key" related to the truth of his father's death, Terutomo wandered around the world, but a series of mysterious property transfers occurred, so he returned to Japan. Then, a person aiming at the "Devil's Key" appeared in front of Terutomo, and he had to challenge the "Devil's Game"...