Hinata Sakurai, an ordinary girl with a secret identity as the Magical Girl Saint Lime, fights against the Viest Army to rescue her missing brother, who once was the heroine Saint Cherry. Now corrupted and transformed into an evil magical girl, Cherry has become her greatest challenge. With the power her brother entrusted to her, Hinata turns her sorrow into rage to save him, facing a great evil while discovering her true desire and nature.

Captured by the Viest Army, Saint Lime continues to resist. To fully break her spirit, the monster Devil Beetle and his new subordinate—the corrupted evil magical girl Bloody Cherry—devise a cruel new plan. They force Lime to watch her admired heroine, Saint Cherry (her transformed older brother/sister), being humiliated and freely used sexually. “Please, do whatever you like to the pathetically defeated Saint Cherry!” Unable to resist her own hidden desires after witnessing the lewd spectacle, Lime finally submits to Beetle. The self-surrendered masochistic magical girl follows the same path as her fallen sibling and is reborn as a new evil heroine. Together with her brother (now permanently a woman after defeat), the newly corrupted Saint Lime announces: “We hereby declare our retirement from being heroines of justice.”