Penerangan：Lux, who was once the strongest Drag-Knight, earned the title of "the weakest undefeated" because he never actively attacked others. Five years ago, he witnessed the destruction of his country due to a revolution. However, when he accidentally broke into the bathhouse of a women's dormitory, he unexpectedly met Lizsharte, the princess of the New Kingdom, and later inexplicably entered a girls' school that trained Drag-Knights. The story of the weakest prince's harem battle began.