The brutal practice of slavery, where a master has complete authority over their slave, had long vanished from contemporary Japan. However, the recent introduction of an ominous device called the Slave Control Method (SCM) has altered the situation. This device grants its user the power to subjugate the individual it targets, allowing them to take vengeance or fulfill their corrupt objectives. Nevertheless, the catch is that two owners must compete in a game, and the victor will dominate the defeated.
Among those who engage with this device are Eiya Arakawa, a carefree part-time worker, and Yuuga Oota, a casual fellow. After their encounter, Oota convinces Arakawa to become his "insurance," providing her with control over him if he loses to another SCM user.
In this competition, devious tactics are favored, and there are no regulations. No one is out of harm's way, as anyone, from business people to well-known club hosts, could become a slave.
