Eric, a prince of the Artos dynasty, intervenes during the conquest of Brinkhofen's capital to save Princess Lotte from battlefield death. Yet Lotte faces public execution in his homeland. To avert this, Eric formally proposes transforming her into his personal slave maid within one month. The king opposes strongly, but Eric’s uncle Karl persuades the monarch to permit the attempt.

Eric’s objective is multifaceted: a successfully trained Lotte would become absolutely loyal, serving simultaneously as sex slave, bodyguard, and maid. As a slave maid, she could also bear Eric’s children to secure the royal succession. Eric facilitates the training under severe time constraints, relying on Kira—a trainer with magical abilities—and rare magical creatures procured by Karl for Lotte’s accelerated conditioning.

Eric shares a childhood friendship with Lotte. His actions—capturing her and initiating her training—are driven by the stated aim of prolonging her life, though the path involves her loss of virginity and submission to a rigorous, degrading transformation into a "sex toy."