"Murder Princess" is a six-volume manga series written and illustrated by Sekihiko Inui. The story is set in a fantastical world where the kingdom of Forland is thrown into chaos following a coup orchestrated by the scientist Dr. Akamashi. During the upheaval, Princess Alita Forland flees the palace to seek help but is pursued by assassins. In a desperate encounter, she crosses paths with Falis, a skilled and ruthless bounty hunter. A magical accident causes their souls to switch bodies, leaving Falis in the princess's form and Alita in Falis's. Despite the unexpected turn of events, Falis reluctantly agrees to protect the kingdom in Alita's place, adopting the title "Murder Princess" as she battles to reclaim Forland.

Falis, now in Alita's body, is a formidable fighter with a no-nonsense attitude, wielding immense strength and combat prowess. Accompanied by her loyal companions—Pete Armstrong, a cyborg with a tragic past, and Dominikov, a stoic and skilled swordsman—Falis confronts Dr. Akamashi and his army of biomechanical monsters. The narrative explores themes of loyalty, identity, and the burden of leadership as Falis grapples with her new role as a protector of the kingdom. Meanwhile, Alita, in Falis's body, provides support from the sidelines, showcasing her resilience and determination to aid her people despite her physical limitations.

The series blends action, fantasy, and dark humor, with a focus on intense battles and character dynamics. Falis's journey is marked by her evolving sense of responsibility and her growing bond with Alita and her allies. The story culminates in a climactic showdown against Dr. Akamashi, revealing the full extent of his twisted experiments and his connection to the kingdom's downfall. "Murder Princess" delivers a compact yet engaging narrative, combining fast-paced action with emotional depth and a unique premise centered on the body-swap trope.