The series follows the life of Kai Houjou, the child of a human woman and the demon king who was kidnapped at birth and held captive in the demon realm, enduring dreadful torture and imprisonment. Escaping to the human world, he sets out to locate and safeguard his mother, but the time difference between the two domains proves to be a hindrance. To remain close to her, Kai takes on the guise of a high school student, but the demons continue to pursue him relentlessly. As he tries to protect his mother and uncover the underlying cause of the demons' fixation on him, he also confronts the traumatic experiences he suffered at the hands of his demon prince step-sibling, including torture and rape.
Despite its compelling storyline, the series handles sensitive themes such as sexual assault, murder, incest, and torture in a serious and reserved tone. Kai's mother is a survivor of trauma, and despite being the subject of ridicule and gossip, she chooses to enroll in school once again. Many of the demons have backgrounds of sexual violence or continue to engage in such behaviors. With suggestive and disturbing themes, the artwork can be unsettling, yet it remains subtle and alluring.
