Cheonhwi, the 'Sword Ghost' who began wielding a sword just to escape hunger, reaches the realm of a supreme master. The Central Plains hurtles toward catastrophe with the emergence of the 'Heavenly Demon,' the greatest martial artist of all time and a calamity to all murim denizens. Cheonhwi forms a deep bond with Tang Sowol, the 'Poison Princess' of the Sichuan Tang Family who was left alone after losing her entire clan to the Heavenly Demon, and joins her in her quest for revenge against him. However, their blades fail to reach the Heavenly Demon, and they meet their deaths on the same day in the same place. If only he had a little more talent. If only he had a little more time. If only he had learned stronger martial arts. At the end of his regrets, Cheonhwi regresses 20 years into the past. Quickly regaining his original strength, the 'boy' Cheonhwi resolves to protect her this time. Thus, he tracks down Tang Sowol—who has just stepped out into the Murim world at nearly twenty years old—and... kidnaps her.