​In the depths of a hidden magical world named Roa, a fierce battle rages on between the all-female knight corps led by Queen Gloria and the monstrous troops of the evil syndicate Zerou. Enter Metzer, an intelligent and young Zerou officer who receives special permission to execute his groundbreaking plan. Transferred to Earth’s surface in secret, Metzer’s mission is to earn the trust of the Sweet Knights, two Japanese girls endowed with the power to protect humanity from Zerou’s monsters. With his newfound knowledge of their vulnerabilities, Metzer skillfully employs his creatures to conquer, capture, and hypnotize the Sweet Knights, transforming them into Zerou’s obedient sex slaves. Little do they realize that Metzer harbors even greater aspirations…​