A man from modern Japan is reborn into a medieval fantasy realm where the norms of chastity and power are completely reversed. In this world, women dominate society and the battlefield while men are sheltered and protected. The protagonist, Faust, grows up to become an anomaly: the worlds only male knight and a celebrated war hero. Raised as a frontier lord, he clings to the values of his past life, which constantly puts him at odds with his new reality. He struggles to maintain his composure amidst the bold advances of powerful women, from a queen whose attire is barely there to a buxom duchess whose diplomacy borders on harassment.

Faust is assigned to mentor the fierce but inexperienced second princess, Valiele, on her first military campaign. What begins as a routine mission to suppress bandits takes a dire turn when they discover that the culprits are reinforced by remnants of a neighboring domains failed succession war. These ruthless forces have ravaged a village, leaving chaos in their wake. Unprepared to face such a large and vicious army, Valieles troops face overwhelming odds. As defeat looms, Zabine, the commander of the royal knights, rallies the common folk to their cause in a unified resistance, a bold strategy that risks extraordinary casualties.

The story follows Faust as he navigates courtly intrigue, battlefield dangers, and the daily trial of protecting his honor and chastity in a female-led society. Key characters include Queen Lizerotte, the mother of Valiele and the first princess Anastasia, who is also a political player in the kingdom. The narrative arc begins with Fausts reincarnation and establishment as a frontier lord, moves through his assignment as Princess Valieles advisor, and escalates into a larger conflict involving the remnants of a succession war and a desperate unified resistance against a vicious army. The central tension balances Fausts internal struggle with his own desires and the external threats of war and political duplicity.