After being framed as a pedophile and executed, Prince Rick's vengeful spirit strikes a deal with the Demon King to possess the body of his adopted sister, Milia, who stole his destiny as the legendary Hero. By using thought manipulation to warp Milia's common sense and morality, Rick begins a cruel campaign to systematically destroy her reputation and lead the arrogant Hero Princess into a spiral of public humiliation and despair.
Milia begins her quest to retrieve three cursed tools: the Rod of Reversal, the Hypnotic Gemstone, and the Cursed Sword. After defeating a monster threatening a village, she visits Academia to seek a legendary treasure. To earn the top rank required to claim it, Milia is tricked into participating in a provocative "educational" demonstration led by a professor. Despite the humiliation, she secures the treasure—a pair of antique bloomers—while the Demon King continues to manipulate her journey from the shadows.
Guided by a manipulative Goddess, Milia ventures into the Succubus Tower to retrieve what she believes is a sacred treasure, only to fall into a trap set by the Demon King. After winning a perverse competition against a succubus, Milia obtains an item that secretly drains her power. As she attempts to travel to her next destination, she continues to succumb to the Goddess's influence, accepting humiliating sexual demands as part of her duty as a hero.