Lavinia was framed by her beloved father and labeled a villainous young lady. To raise funds for her revenge, she chose Hotel Alheim, a converted Demon King's castle. She tried to seduce the handsome young general manager, Ruudbert, a descendant of the Demon King, and seize management rights, but her attempt failed quickly. However, Lavinia, who aims to rise to power, uses her "knowledge of evil" to solve the problems of guests one after another. A tale of ambition and humanity unfolds at the Demon King's hotel! (Source: Kadokawa, translated)